effects of low-level radioactive-waste disposal on water chemistry … · 2011-03-07 · eters...

Effects of Low-Level Radioactive-Waste Disposal on Water Chemistry in the Unsaturated Zone at a Site Near Sheffield, Illinois, 1982-84

By C.A. PETERS, R.G. STRIEGL, P.C. MILLS, and R.W. HEALY

U.S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 2390

U.S. DEPARTMENT OF THE INTERIOR

MANUEL LUJAN, Jr., Secretary

U.S. GEOLOGICAL SURVEY

Dallas L. Peck, Director

Any use of trade, product, or firm namesin this publication is for descriptive purposes onlyand does not imply endorsement by the U.S. Government

UNITED STATES GOVERNMENT PRINTING OFFICE: 1992

For sale byBook and Open-File Report Sales U.S. Geological Survey Federal Center, Box 25286 Denver, CO 80225

Library of Congress Cataloging in Publication Data

Peters, C.A.Effects of low-level radioactive-waste disposal on water chemistry in the

unsaturated zone at a site near Sheffield, Illinois, 1982-84 / by C.A. Peters ... [et al.].

p. cm. (U.S. Geological Survey water-supply paper ; 2390)Includes bibliographical references.1. Radioactive waste disposal in the ground Environmental aspects Illi

nois Sheffield Region. 2. Tritium Analysis. 3. Hazardous waste sites Illinois Sheffield Region Zone of aeration. I. Peters, C.A. II. Series.

TD898.12.I3E34 1993 92-5127628.1 '685-dc20CIP

CONTENTS

Abstract 1 Introduction 1

Purpose and Scope 1 Site History 1 Related Studies 5 Acknowledgments 5

Description of Study Area 5 Climate 5 Geology 5 Hydrology 6

Methods of Investigation 8Collection and Analysis of Geologic Materials 8 Collection and Analysis of Water Samples 9

Water Analysis 9Collection of Precipitation Samples 9 Collection of Water Samples From the Unsaturated Zone 11 Collection of Water Samples From the Saturated Zone 15

Interpretive Techniques 15 Properties of Geologic Materials 17 Chemistry of Water Samples 18

Precipitation 18 Unsaturated-Zone Pore Water 18

Undisturbed Unsaturated Zone, Borehole 585 18 Disturbed Unsaturated Zone, Above Trench 20 Disturbed Unsaturated Zone, Below Trench 20

Saturated-Zone Water 24 Effects of Radioactive-Waste Disposal on Water Chemistry in the Unsaturated

Zone 26 Affected Constituents 26

Carbonate Minerals 26 Sulfate 29Other Inorganic Constituents 29 Dissolved Organic Carbon 32 Tritium 33

Contributing Influences 35 Summary 37 Selected References 38

FIGURES

1-3. Maps showing:1. Location of Sheffield disposal site 22. Topography at the Sheffield site 33. Location of trenches, tunnel, and borings used to determine physical and

chemical properties of geologic materials and soil gas at the Sheffield site 4

Contents III

4, 5. Diagrams showing:4. Side and end views of a typical trench 55. Time-stratigraphic and rock-stratigraphic classification of the Illinois State

Geological Survey 66. Map showing location of lines of section, lysimeters, wells, and precipitation

collector 77. Geologic section A-A' of the Sheffield site 88. Geologic section B-B' of the Sheffield site 99. Map showing surface- and ground-water drainage, including the strip-mine

lake 1010. Geologic section A-A' showing probable flow paths in the unsaturated

zone 1111. Schematic diagram showing typical installation of pore-water pressure-

vacuum lysimeter 1212. Geologic section showing lysimeter locations off-site 1413. Geologic section C-C' showing on-site, above-trench lysimeter locations 1514. Geologic section A-A' showing lysimeter locations in trench caps and in the

tunnel 16 15, 16. Piper diagrams showing:

15. Ionic composition of water collected from off-site lysimeters and precipitation 19

16. Ionic composition of pore water collected from on-site, above-trench lysimeters 21

17. Graph showing seasonal trends in evapotranspiration and soil saturation, and tritium concentrations at two above-trench lysimeter locations from July 1982 through June 1984 22

18. Piper diagram showing ionic composition of pore water collected from on-site, below-trench lysimeters in the Hulick Till Member of the Glasford Formation 23

19, 20. Graphs showing:19. Seasonal trends in tritium concentrations in pore water from three below-

trench lysimeters from November 1982 through May 1984 2520. Tritium concentrations in pore water from three below-trench lysimeters

from November 1982 through May 1984 26 21. Piper diagram showing ionic composition of water collected from the

saturated zone 27 22-28. Graphs showing:

22. Relation of dolomite saturation index to calcite saturation index 2823. Average concentrations of calcium, magnesium, and sodium in pore

water from lithologic units on-site and off-site from July 1982 through May 1984 30

24. Average concentration of sodium in pore water relative to average per centage of montmorillonite in the clay-mineral fraction of four lithologic units off-site from October 1982 through May 1984 31

25. Calcium content of geologic materials and molar ratios of calcium to magnesium in pore water relative to depth and geologic material off-site 31

26. Average concentration of sulfate in pore water from lithologic units on-site and off-site from July 1982 through May 1984 32

27. Average concentration of silica in pore water from above-trench and below-trench lysimeters from August 1982 through May 1984 33

28. Average concentration of tritium in pore water and ground water from July 1982 through May 1984 34

IV Contents

29. Diagram showing generalized flow paths of water in the unsaturated and saturated zones, and reactions occurring in each lithologic unit 35

30. Box and whisker plots showing statistical summary of selected chemical properties in pore water in lithologic units on-site and off-site from June 1982 through June 1984 36

TABLES

1. Laboratory procedures for analyses of physical and chemical properties of geologic materials 43

2. Concentrations of selected constituents for a known water sample, for the known sample collected through a leached porous-ceramic cup, and the percentage of difference between the concentrations 43

3. Mean concentrations of selected metals in water samples collected using lysimeters that contain, and that do not contain, galvanized material 43

4. Values of specific conductance, pH, alkalinity (as CaCO3), and chloride for untreated and for silica-saturated solutions from well 505, distilled water, and distilled water acidified to pH 2.7 with sulfuric acid 44

5. Concentrations of selected constituents in pore water collected at 20 and 80 kilopascals suction 44

6. Concentrations of selected constituents for uncomposited and composited pore-water samples 44

7. Mean values of physical properties for geologic materials 448. Mean values of chemical properties for geologic materials 459. Mean values of mineralogic properties for geologic materials 45

10. Mean, standard deviation, and number of pore-water samples analyzed for selected constituents at off-site (borehole 585) lysimeters 46

11. Mean, standard deviation, and number of pore-water samples for selected constituents at on-site lysimeters 47

12. Equilibrium constants used in calculation of saturation indices 4913. Saturation indices for calcite and dolomite on-site and off-site 4914. Physical characteristics of water-chemistry sampling sites 5015. Chemical analyses of precipitation 5016. Chemical analyses of pore water in the unsaturated zone from off-site 5117. Chemical analyses of pore water in the unsaturated zone from on-site, above-

trench locations 5418. Chemical analyses of pore water in the unsaturated zone from on-site, below-

trench locations 6219. Tritium concentrations in pore water from soil cores 7120. Chemical constituents in saturated-zone water 73

Contents

CONVERSION FACTORS AND VERTICAL DATUM

Metric (International System) units used in this report may be converted to inch-pound units by use of the following conversion factors:

Multiply metric unit

micrometer (|xm)millimeter (mm)

meter (m)kilometer (km)

cubic meter (m3)hectare (ha)

kilogram (kg)gram (g)liter (L)liter (L)

milliliter (mL)gram per cubic centimeter (g/cm3)

square meter per gram (m2/g)kilopascal (kPa)

degree Celsius (°C)nanocurie (nCi)

nanocurie per liter (nCi/L)nanocurie per liter (nCi/L)picocurie per gram (pCi/g)milligrams per liter (mg/L)

micrograms per liter (|xg/L)milligrams per liter calcium carbonate

(mg/L CaCO3)

Multiply

milligrams per liter (mg/L)milligrams per liter (mg/L)

bicarbonate (HCO3 ~)calcium (Ca++)

chloride (Cl~)iron (Fe)

magnesium (Mg++)silica (SiO2)

sodium (Na+ )strontium (Sr++ )sulfate (SO4 )

zinc (Zn++)

By

0.000039370.039373.2810.6214

35.312.4712.2050.035270.2642

33.820.033820.5782

304.20.14500.009869

°F=1.8x°C+320.02702

37.01310.6

0.037011.001.001.219

By

FlF2

Fl

0.01639.04990.02821

.08229

.04350

.02283

.02082

.03059

To obtain inch-pound unit

inch (in.)inch (in.)foot (ft)mile (mi)cubic foot (ft3)acrepound, avoirdupois (Ib avdp)ounce, avoirdupois (oz avdp)gallon (gal)ounce, fluid (oz)ounce, fluid (oz)ounce per cubic inch (oz/in3)square foot per ounce (ft2/oz)pound-force per square inch (lbf/in2)atmosphere (atm)degree Fahrenheit (°F)becquerel (Bq)becquerel per liter (Bq/L)tritium unit (TU)becquerel per gram (Bq/g)parts per million (ppm)parts per billion (ppb)milligrams per liter bicarbonate(mg/L HCO3)

To obtain

milliequivalents per liter (meq/L)millimoles per liter (mmols/L)

F2

0.01639.02495.02821.01791.04114.01664.04350.01141.01041.01530

Sea level: In this report "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929) a geodetic datum derived from a general adjustment of the first-order level nets of both the United States and Canada, formerly called Sea Level Datum of 1929.

VI Contents

Effects of Low-Level Radioactive-Waste Disposal on Water Chemistry in the Unsaturated Zone at a Site Near Sheffield, Illinois, 1982-84By C.A. Peters, R.G. Striegl, P.C. Mills, and R.W. Healy

Abstract

A 1982-84 field study defined the chemistry of water collected from the unsaturated zone at a low-level radioactive-waste disposal site near Sheffield, Bureau County, III. Chemical data were evaluated to determine the principal, naturally occurring geochemical reactions in the unsaturated zone and to evaluate waste-induced effects on pore-water chemistry.

Samples of precipitation, unsaturated-zone pore water, and saturated-zone water were analyzed for spe cific conductance, pH, alkalinity, major cations and anions, dissolved organic carbon, gross alpha and beta radiation, and tritium. Little change in concentration of most major constituents in the unsatu rated-zone water was observed with respect to depth or distance from disposal trenches. Tritium and dissolved organic carbon concentrations were, however, dependent on proximity to trenches. The primary reactions, both on-site and off-site, were carbonate and clay dissolution, cation exchange, and the oxidation of pyrite.

The major difference between on-site and off-site inorganic water chemistry resulted from the removal of the Roxana Silt and the Radnor Till Member of the Glas- ford Formation from on-site. Off-site, the Roxana Silt contributed substantial quantities of sodium to solution from montmorillonite dissolution and associated cation- exchange reactions. The Radnor Till Member provided exchange surfaces for magnesium.

Precipitation at the site had an ionic composition of calcium zinc sulfate and an average pH of 4.6. Within 0.3 meter of the land surface, infiltrating rainwater or snowmelt changed to an ionic composition of calcium sulfate off-site and calcium bicarbonate on-site and had an aver age pH of 7.9; below that depth, pH averaged 7.5 and the ionic composition generally was calcium magnesium bicarbonate. Alkalinity and specific conductance differed primarily according to composition of geologic materials. Tritium concentrations ranged from 0.2 (detection limit) to 1,380 nanocuries per liter.

The methods of constructing, installing, and sam pling with lysimeters were evaluated to ensure data reli ability. These evaluations indicate that, with respect to

most constituents, the samples retrieved from the lysim eters accurately represented pore-water chemistry.

INTRODUCTION

Disposal of low-level radioactive waste in Pleistocene and Holocene deposits near Sheffield, Bureau County, 111. (fig. 1), has caused rearrangement of existing geologic materials and placed chemically reactive and potentially hazardous substances in the unsaturated zone. To improve understanding of the hydrologic effects of the disposal operations, the U.S. Geological Survey began a series of field investigations at the disposal site in 1976. This study of the hydrogeochemistry of the unsaturated zone is one part of that research effort.

Purpose and Scope

This report details the changes in the chemistry of pore water as it infiltrates areas undisturbed and disturbed by waste-disposal operations. The report (1) describes the techniques used to obtain representative samples of geo logic materials and water from the unsaturated zone; (2) describes the chemistry of geologic materials and water in the unsaturated and saturated zones at off-site and on-site locations; and (3) infers, by statistical analysis and use of geochemical models, the geochemical reactions that occur naturally in the unsaturated zone and the effects of low-level radioactive-waste disposal on pore-water chemistry.

Site History

The Sheffield low-level radioactive-waste disposal site is located on 8.1 hectares of rolling terrain 5 km (kilometers) southwest of Sheffield, 111. (figs. 1 and 2). The site was established by authority of the 1963 Illinois Radioactive Waste Act to dispose of wastes generated in Illinois by nuclear plants, hospitals, medical research facil-

Introduction

89°30'

89°50'

41°30'

jMARSHALL COUNTY

EXPLANATION

NATIONAL WEATHER SERVICE STATION

Figure 1. Location of Sheffield disposal site.

ities, and industry. Twenty-one trenches (fig. 3) were excavated and filled with solidified low-level radioactive waste. The trenches were backfilled with earthen material, and for some trenches, a layer of clayey silt was compacted over the backfill. The compacted layer inhibits the infiltra

tion of precipitation into the trenches. Additional earthen material was mounded lengthwise over the trenches to form ridges that direct runoff from the trench caps (fig. 4).

Burial of waste at the disposal facility was terminated in 1978 because all licensed space had been used. During

2 Effects of Low-Level Radioactive-Waste Disposal on Water Chemistry, III., 1982-84

89

° 47

' 45

41°

20'

3389°

47'

00"

She

ffiel

d ra

dioa

ctiv

e -

was

te

site

bou

ndar

y

EX

PL

AN

AT

ION

TOPO

GR

APH

IC C

ON

TOU

R - S

how

s ap

prox

imat

e at

titud

e of

land

sur

face

. D

ashe

d w

here

infe

rred.

C

onto

ur in

terv

al 5

met

ers.

D

atum

is s

ea le

vel

Jll

400

FE

ET

INTE

RM

ITTE

NT

STR

EA

M

I I

20

" -

s 41°

20'

10'

3 c Fi

gure

2.

Top

ogra

phy

at t

he S

heffi

eld

site

(m

od

ifie

d f

rom

Gar

klav

s an

d H

ealy

, 19

86,

fig.

5'3)

.

I o

89

° 47'

45

41°

20'

33 30"

10'

05

89

° 4

7'

00

'

L~L

_T~~

1^

She

ffiel

d ra

dioa

ctiv

e-

~ ~

~

EX

PL

AN

AT

ION

TR

EN

CH

AN

D D

ES

IGN

ATI

ON

INTE

RM

ITTE

NT

ST

RE

AM

£11

° B

OR

ING

FO

R T

RE

NC

H-C

OV

ER

INS

TRU

ME

NT

(

BO

RIN

G F

OR

TU

NN

EL

INS

TRU

ME

NT

200

400

FE

ET

§

||

®

BO

RIN

G F

OR

OB

SE

RV

AT

ION

WE

LL

41°

20'

10

_ 3

- Lo

catio

n o

f in

ch

es,

,un

ne,

, an

d bo

ring

s us

ed ,

o d

efi

ne

phy

sica

, an

d c

he

.ic

a,

BOR

ING

FO

R G

AS S

AMPL

ING

J_

__

__

__

_

prop

ertie

s o

f ge

olog

ic m

ater

ials

and

soi

l ga

s at

She

ffie

ld

t9. Im

10.6 n t 0.3m

'"I 1 "" "' ""'"" "' ' "V '"" "" '""I-P

_ _-Sump pipe

silt

French drain

SIDE VIEW

Collection sump

Data-collection techniques used in this and other unsaturated-zone investigations at the site are described in Healy and others (1986). A tunnel originally constructed for the study by Foster and others (1984) was used to provide access for sampling directly beneath several trenches on-site. The 90-m-long by 2-m-diameter tunnel extends northward under the eastern ends of trenches 11, 3, 2, and 1 (fig. 3).

Earth-fill mound

Compacted clayey silt

French drain 0.6m*-l U

END VIEW

DIMENSIONS IN METERS <n) NOT TO SCALE

Figure 4. Side and end views of a typical trench (modified from Foster and others, 1984, fig. 4).

Acknowledgments

The authors acknowledge the Illinois Department of Nuclear Safety for tritium analyses; the University of Illinois, Department of Geology, for analysis of carbonate mineralogy, cation-exchange capacities, petrography, and tritium concentrations; the Illinois Environmental Protec tion Agency for water-chemistry analysis; and the Illinois State Geological Survey for determination of grain-size distributions and clay mineralogy. We would like to express our appreciation to US Ecology, Inc., the firm responsible for site management, for allowing access to the site for our investigation.

the period 1967-78, nearly 90,500 m3 (cubic meters) of waste were buried, including 13,000 g (grams) of plutonium-239, 1.7 g of uranium-233, 40,000 g of uranium- 235, and 270,000 kg (kilograms) of source material (K. Dragonette, U.S. Nuclear Regulatory Commission, written commun., 1979). The buried wastes include such items as resins, the carcasses of laboratory animals, sorbed liquids, glassware, building materials, clothing, containerized gases, paper, and cleanup materials (Foster and others, 1984). Containment vessels for these materials include steel drums, wooden crates, plastic containers, concrete casks, and cardboard cartons. A chemical-waste disposal facility is located northwest of the site and is separated by a 60-m (meter)-wide buffer zone.

Related Studies

Reports on hydrology, geology, and water quality at the Sheffield site (Foster and Erickson, 1980; Foster and others, 1984, 1984a, and 1984b) provided much of the background information for this study. A Brookhaven National Laboratory study (Piciulo and others, 1982) con tributed information on chemical and physical properties of geologic materials in the unsaturated zone. Other investi gations of the unsaturated zone at the site concern the role of trench caps in inhibiting infiltration (Healy, 1989), the determination of evapotranspiration from trench caps (Healy and others, 1989), the modeling of unsaturated-zone waterflow (Mills and Healy, 1991), and a study of gas transport (Striegl, 1988).

DESCRIPTION OF STUDY AREA

Climate

The climate at Sheffield is continental, characterized by an average annual temperature of 10°C (degrees Celsius) (State of Illinois, 1958), with warm, humid summers (average temperature, 22.2°C) and cold winters (average temperature, 7.5°C) (Wallace, 1980, p. 26-28). Average annual precipitation computed from records of three National Weather Service stations located within 25 km of the site (fig. 1) was 890 mm (millimeters) for the period 1939 through 1979 (U.S. Department of Commerce, 1939-79). There is a dry period, November through March; a wet period, April through July; and a moderate period, August through October. During the study, monthly pre cipitation averaged 49.3 mm during the dry period, 107 mm during the wet period, and 80.8 mm during the moderate period. Additional information concerning precipitation and evapotranspiration can be found in Healy and others (1989).

Geology

The site is located in the Galesburg Plain Division of the Till Plains Physiographic Region (Thornburn, 1963) and is characterized by Illinoisan till plains that have an undu- lant surface. The tills have weathered zones up to 2 m thick and leached zones up to 4 m thick (Piskin and Bergstrom, 1975, p. 11-17). Present topography generally reflects the preglacial bedrock surface.

Description of Study Area

TIME STRATIGRAPHY

LJ

CO

CO

CC.

Z.a:LJ

^o

z.

z.

JHco>-zcoLJ Q.

LJ2 COLJ LJ

£|LJ

X

COLJ(T LJ

LJ zLJ 0O

CO

Q.

Z. <

2 Ll 1 ___

COLJQ

WISCONSINANSTAGE

SANGAMONIANSTAGE

ILLINOIAN STAGE

ROCK STRATIGRAPHY

< 2

S^53

<E to 0 LJLJ OQ. -I

<<!n§ CO

z.o

a: oLL.

g

e>

BERRY CLAYMEMBER

RADNOR TILLMEMBER

TOULONMEMBER

HULICK TILL MEMBER

DUNCAN MILLSMEMBER

CARBONDALE FORMATION

Figure 5. Time-stratigraphic and rock-stratigraphic classifi cation of the Illinois State Geological Survey (modified from Willman and Frye, 1970, fig. 1).

The stratigraphic nomenclature used in this report is that of the Illinois State Geological Survey (Willman and Frye, 1970, p. 12) and does not necessarily follow the usage of the U.S. Geological Survey. Figure 5 shows the time- stratigraphic and rock-stratigraphic classifications.

Quaternary deposits form the unconsolidated geo logic cover and vary in thickness from 3 to 28 m. These deposits include eight rock-stratigraphic units (fig. 5) (Fos ter and others, 1984) that range in lithology from a silty clay to a pebbly sand. Areal and vertical distribution of these units varies greatly across the site (figs. 7 and 8, lines of section in fig. 6). The units overlie about 140 m of bedrock composed of fossiliferous shale, coal, and mudstone of the Pennsylvanian Carbondale Formation (H.W. Smith, Illinois State Geological Survey, written commun., 1966).

The oldest Quaternary deposit at the Sheffield site (fig. 5) is the Pleistocene Duncan Mills Member of the Glasford Formation (Willman and Frye, 1970, p. 12) that consists of silt interbedded with silty clay and some pebbly silty-sand layers. The next oldest unit is the Hulick Till

Member of the Glasford Formation. The textural composi tion of the Hulick Till Member ranges from clayey silt to sandy silty clay.

The Toulon Member of the Glasford Formation, a channellike outwash deposit, consists of a well-sorted, pebbly sand grading to a pebbly silty sand. The Radnor Till Member of the Glasford Formation, present only in the southern half of the site, consists of a clayey silt or a sandy silty clay (Foster and others, 1984, p. 14). The Berry Clay Member of the Glasford Formation is an accretion-gley deposit; because it is restricted to a few locations in the western part of the site, it was not evaluated in this study.

During the Wisconsinan, glacial ice did not cover the Sheffield site; eolian and other postglacial materials were deposited there. Wisconsinan eolian deposits are designated as the Roxana Silt and the Peoria Loess. Deposition of Cahokia Alluvium, a sandy silt, began in the Wisconsinan and extended into the Holocene; because it is restricted to the northeastern corner of the site, it was not evaluated in this study.

The last major soil development began in the Holo cene and continues to the present. This soil is developed in the upper part of the Peoria Loess and has been designated as Modern soil. The uppermost layer of material at the site is the fill material, brought in for construction of trench caps and to fill low areas. Composition of the fill ranges from silt to silty clay (Foster and others, 1984, p. 15).

Hydrology

The average annual precipitation measured at the site for the period July 1982 through June 1984 was 948 mm (Mills and Healy, 1991). Mills and Healy (1991) also estimated that average annual evapotranspiration was 657 mm, runoff was 220 mm, and recharge to the unsaturated and (or) saturated zone was 131 mm. Runoff that originates on the site drains to Lawson Creek, about 1.6 km east of the site (fig. 9).

Ground water in the Pleistocene deposits flows to the east and discharges to a strip-mine lake 0.4 km from the site (fig. 9). Ground-water flow is primarily within the pebbly sand of the Toulon Member. Altitude to the saturated zone ranges from 8 to 16 m and is highly variable. The altitude of the water table beneath the study area changes by as much as 6 m over a distance of 60 m.

All of the Quaternary deposits that have been identi fied at the site are present within the unsaturated zone. All trenches, with the possible exception of trench 18, were constructed entirely within the unsaturated zone.

Percolation of water to the saturated zone generally occurs only during spring. The rest of the year there is less water movement in the unsaturated zone because of frozen ground and low precipitation in the winter, high evapotran-


--~*

502«

505

NOT TO SCALEEXPLANATION

TRENCH AND DESIGNATION

C3Z3 TUNNEL

A .^.LINE OF SECTION

a BOREHOLE AND DESIGNATION-# PRECIPITATION COLLECTOR

WELL AND DESIGNATION >502 well sampled in study

508 Well used for geologic control in cross-section

PRESSURE-VACUUMLYSIMETER AND DESIGNATION

® Above-trench 65 Be low-trench 585 Off-site

Figure 6. Location of lines of section, lysimeters, wells, and precipitation collector.

spiration during the summer, and moderate precipitation during the fall.

Water movement through the unsaturated zone is complex because of seasonal variations of precipitation and evapotranspiration, physical heterogeneity of the waste trenches, and variability in areal distribution and physical character of the unconsolidated surficial deposits. The direction of water movement within the unsaturated zone is primarily downward. The layering of the different geologic units affects the direction as well as the rate of water movement (Mills and Healy, 1987). Sloping interfaces between geologic units, as shown in figure 10, may function as preferential pathways, adding a horizontal component to unsaturated-zone flow. Throughout the length

of the tunnel, the sand-silt-clay Hulick Till Member is overlain by well-sorted, medium-grained sand of the Tou lon Member. The saturated hydraulic conductivity for the sand is about three orders of magnitude greater than for the till (Foster and others, 1984, p. 18), and the interface between the sand and till units has a steep slope near the north end of the tunnel (fig. 10). Because the hydraulic conductivity for the till is much less than for the sand, the water content of the sand becomes nearly saturated at the interface, and water tends to move along the interface instead of through the till (Foster and others, 1984, p. 17). The effects of interfaces between other units are more difficult to interpret because the differences in hydraulic conductivity are smaller and interface slopes are not nearly

Description of Study Area

Peorial . /: ;: j Loess L -J::::

225

EXPLANATION

GLASFORD FORMATION Compacted Layer (not to scale)

50 100 FEET

10 20 30 METERS

TRENCH AND DESIGNATION

GEOLOGIC CONTACT

VERTICAL EXAGGERATION x5 DATUM IS SEA LEVELL-Lj

...T.. WATER TABLE

Figure 7. Geologic section A-A' of the Sheffield site. (See fig. 6 of this report for location of line of section.)

as steep as for the sand/till interface. Figure 10 also shows probable flow paths for water movement through the unsaturated zone at geologic section A-A'. Ground-water flux along each of these paths was not quantified.

METHODS OF INVESTIGATION

Collection and Analysis of Geologic Materials

Physical and chemical properties of geologic materi als were determined from core samples removed during the drilling of boreholes and the installation of sampling equip ment. Physical properties tested included particle-size dis tributions, surface area, bulk density, and porosity. Chem ical properties tested were carbonate and clay mineralogies; petrography of fine sands; cation-exchange capacity; exchangeable calcium, magnesium, and iron concentra

tions; pH; and percentage of organic content. Geologic materials were analyzed according to methods outlined in table 1. Figure 3 shows locations where samples were collected for analyses of physical and chemical properties.

Samples of fill material, Peoria Loess, and the Toulon Member and the Hulick Till Member of the Glas- ford Formation were obtained during installation of many of the lysimeters and were analyzed for the above-listed physical properties and gross alpha and beta radiation. Gamma-spectral analyses for nonnaturally occurring gamma-emitting radionuclides and high concentrations of naturally occurring gamma-emitters were performed on four cores collected from between the top of the tunnel and the bottom of trenches 2 and 3.

Samples of fill material, Peoria Loess, Roxana Silt, Radnor Till Member of the Glasford Formation, and Toulon Member from nine different well borings (Foster and others, 1984b) were analyzed for particle-size distribution, mineralogic composition, clay mineralogy, and cation-


eMETERS

245-1

240-

230-

225-

220-

' ' ' ' ' Toulon Member ;| |; ; ; ; ':: TjjjririeJ:7%/.:

508

90 METERS

VERTICAL EXAGGERATION x5 DATUM IS SEA LEVEL

EXPLANATION

GLASFORD FORMATION

|~ "Compacted Layer (not to scale)

J TRENCH AND DESIGNATION

GEOLOGIC CONTACT- Dashed where inferred

WELL AND DESIGNATION

? BOREHOLE AND DESIGNATION

Figure 8. Geologic section B-B' of the Sheffield site. (See fig. 6 of this report for location of line of section.)

exchange capacity. Samples of the Peoria Loess, Roxana Silt, Radnor Till Member, Toulon Member, and Hulick Till Member also were analyzed for cation-exchange capacity, pH, calcium, magnesium, iron, and percentage of iron, percentage of carbonates, and percentage of organic matter (Piciulo and others, 1982).

Samples of geologic materials were obtained by driving 25-, 50-, or 75-mm-diameter sampling tubes into sediments and by using split-spoon samplers. Samples were removed from the tubes by extrusion or by cutting the tube lengthwise (Healy and others, 1986, p. 29).

Sample-collection procedures can introduce substan tial error in physical and chemical measurements. Stainless- steel samplers were used to prevent chemical reactions that may occur between wet soils and samplers. Cores were sealed from the atmosphere during storage to prevent loss of water by evaporation.

Collection and Analysis of Water Samples

Water samples were collected from a rain collector, pore-water pressure-vacuum lysimeters, ground-water observation wells, and soil cores. Specific conductance, pH, alkalinity, and concentrations of major cations, anions, dissolved organic carbon (DOC), gross alpha and beta radiation, and tritium were measured in water samples.

Tritium is a radioisotope of hydrogen that decays by pure beta emission and has a half-life of 12.3 years.

Water Analysis

Specific conductance was measured in the field for all sample volumes greater than 10 mL (milliliters). Measure ments of pH in water were made in the field using a pH meter and combination glass electrode (Skougstad and others, 1979, p. 543). Mean pH values were derived by converting pH units to hydrogen-ion concentrations, deter mining mean concentrations, and converting the means back to pH units.

Alkalinity was determined by incremental electromet- ric titration (Barnes, 1964, p. 17) using 5 to 100 mL of sample. For the range in pH that was measured, titrated alkalinity was assumed to be bicarbonate-ion alkalinity.

Major ions, metals, and DOC were analyzed at the Illinois Environmental Protection Agency (IEPA) lab using methods described by IEPA (1982) and at the U.S. Geo logical Survey National Water Quality Laboratory in Doraville, Ga., using methods described by Skougstad and others (1979). Samples for metals analysis were acidified in the field with nitric acid to a pH of 2 and were kept chilled. Samples for DOC analysis were filtered through a silver filter in the field using a stainless-steel filter chamber. DOC samples were kept chilled and dark until analyzed.

Gross alpha and beta radiation were measured with a NMC Model PC-5 gas proportional counter (Nuclear Meas urements Corporation, 1975). Tritium concentrations were measured by liquid scintillation (Thatcher and others, 1977, p. 63-71). Two counts of 200 minutes each were made of each sample, using a Beckman LS100 scintillation counter. Duplicate counts, analyses of replicate samples by other labs, and longer-than-recommended count periods were employed for quality control.

The limit of detection of tritium by the liquid-scintil lation counting method is about 0.2 nCi/L (nanocuries per liter) (62.1 tritium units) (Thatcher and others, 1977, p. 79); this value is considered to be the background concentration of tritium at the Sheffield site. The accuracy of the method used for tritium analysis did not allow determination of actual tritium concentrations; the method did allow distin guishing between values at ± 10 percent.

Collection of Precipitation Samples

Precipitation samples were collected using a stainless- steel rain collector with a 300-mm opening on top that drained immediately into a polyethylene bottle (Bracken- siek and others, 1979, p. 32-36). The collector was located at a height of 2.5 m above land surface near borehole 585 (fig. 6). The precipitation-collection system was cleaned with laboratory-glassware detergent and rinsed thoroughly with distilled water before each sample was collected. Samples were collected from six rainstorms between June

Methods of Investigation

89

° 47

' 45

41°

20'

331

0'

05

'

I I I a

89

° 47'

00"

2Q»

-. S

heffi

eld

radi

oact

ive -

was

te s

ite b

ound

ary X

^

EX

PL

AN

AT

ION

WA

TER

-TA

BLE

CO

NT

OU

R-

Sho

ws

appr

oxim

ate

altit

ude

of

wat

er ta

ble

in s

hallo

w a

quife

r Ju

ne 1

982.

Con

tour

inte

rval

2

met

ers.

D

atum

is s

ea le

vel

GR

OU

ND

-WA

TER

DIV

IDE

GR

OU

ND

-WA

TER

FLO

W P

ATH

INTE

RM

ITTE

NT

STR

EA

M

; -s

200

400

FE

ET

|

41°

20. ..

.I

__

__

__

__

__

,__

__

__

__

_0

50

100M

ET

ER

S_____________________

Figu

re 9

. S

urf

ace-

an

d g

rou

nd

-wate

r d

rain

age,

in

clu

din

g t

he

str

ip-m

ine l

ake

(mo

dif

ied

fro

m C

arkl

avs

an

d H

ealy

, 19

86,

fig

. 10

).

230-

225EXPLANATION

GLASFORD FORMATION I Compacted Layer (not to scale)

L _L J TRENCH AND DESIGNATION

50i100 FEET

10 20 30 METERS


GEOLOGIC CONTACT

FLOW DIRECTION AND RELATIVE MAGNITUDE

WATER TABLE

Figure 10. Geologic section A-A' showing probable flow paths in the unsaturated zone (modified from Mills and Healy, 1991, fig. 43). (See fig. 6 of this report for location of line of section.)

and December 1983. Specific conductance, pH, alkalinity, and tritium concentrations were measured for_all samples, and major ions were analyzed for three samples.

High values of zinc in precipitation samples sug gested possible contamination problems. To determine if the samples were contaminated with zinc by the collection apparatus, distilled water (pH 5.9) was poured through the apparatus and then analyzed for zinc. The average concen tration of zinc in these samples was 40 |j,g/L (micrograms per liter) as compared to an average zinc concentration in rainwater of 1,300 |xg/L.

Collection of Water Samples From the Unsaturated Zone

Pore-water pressure-vacuum lysimeters (vacuum lysimeters) were used to collect pore-water samples from the unsaturated zone. Vacuum lysimeters consist of a porous-ceramic cup attached to one end of a cylinder that has an air-tight plug fitted in its other end. Two tubes lead

through the plug into the cylinder, one ending near the plug and the other ending proximal to the base of the cup. The tubes lead to land surface where each is terminated with a gas-tight valve (fig. 11). To collect water, a vacuum that exceeds the existing soil-water tension is applied to the lysimeter (Healy and others, 1986, p. 28). The resulting pressure gradient causes water to flow through the ceramic cup into the lysimeter. Pore-water samples are withdrawn by opening the valves on the access tubes and applying positive pressure with compressed nitrogen gas to the upper tubing, forcing water up the lower access tube and out of the lysimeter. Details of construction and installation of vac uum lysimeters are described by Healy and others (1986). Pore-water samples are filtered as they pass through the lysimeter cup; therefore, only dissolved fractions were measured.

Vacuum lysimeters allow numerous samples to be obtained from the same location at a relatively inexpensive

Methods of Investigation 11

dr^ 3dJ

Silicon tubex

Pinch clamp

3-millimeter diameter nylon tube

Pressure-vacuum hand pump

73-millimeter diameter polyvinylchloride (PVC) pipe

Ceramic cup

Polyethylene sample bottle

-Grout seal

Backfill material

Bentonite seal

Silica flour

NOT TO SCALE

Figure 11. Typical installation of pore-water pressure-vacuum lysimeter.

cost. Several problems are inherent in their operation: (1) The materials from which lysimeters are constructed can contribute constituents to, or remove constituents from, the sample obtained; (2) the application of suction to retrieve lysimeter samples can change the natural pore-drainage rate or can sample an area rather than a point; and (3) the application of suction can change the chemical equilibria of the sample as it is drawn into the lysimeter.

The porous-ceramic cup has been shown to contribute several milligrams per liter of calcium, magnesium, sodium, bicarbonate, and silica to water samples (Wolfe, 1967) and to reduce dissolved-metals concentrations in samples by as much as 5-10 percent (Tsai and others, 1980). To avoid similar uncertainties, lysimeter cups used in this study were leached with hydrochloric acid and rinsed with distilled water until the specific conductance of dis tilled water drawn through the cups did not increase. The effect of the leached cups on water chemistry was tested by

drawing a water sample of known constituent concentra tions through a leached cup and analyzing the sample. The known water concentrations, leached-cup water-sample concentrations, and the percentages of change between the two are shown in table 2. The analyses indicated that although major ions were only slightly altered, metals concentrations were subject to large changes.

The potential for contamination of samples by other lysimeter materials (polyvinyl chloride, brass, stainless steel, and galvanized metal) also was investigated by comparing chemical analyses from similarly situated lysim eters constructed with the various materials. Results indi cated that the use of galvanized materials in lysimeter construction may have an effect on concentrations of zinc and manganese (table 3). Concentrations of zinc and man ganese from lysimeters constructed with some galvanized material averaged 50 percent and 160 percent higher, respectively, than concentrations from lysimeters con-

12 Effects of Low-Level Radioactive-Waste Disposal on Water Chemistry, Ml., 1982-84

structed without galvanized materials. The use of other materials in lysimeter construction showed no noticeable effects.

During installation, the borehole annulus surrounding the lysimeter cups was packed with silica flour to reduce clogging by finer soil particles and to ensure good contact between the cup and the surrounding geologic material. To test the effect of silica flour on water chemistry, one lysimeter was installed without silica flour. Chemical anal yses of water from the control and the silica-packed lysimeters were similar. In a laboratory study, water col lected from well 505, distilled water, and distilled water acidified with sulfuric acid to pH 2.7 were mixed with silica flour, filtered, and analyzed for specific conductance, pH, alkalinity, and chloride. Those measurements, and meas urements for aliquots of the same waters not mixed with silica flour, are listed in table 4. Results indicate that water mixed with silica flour was very similar to untreated water for the four constituents. Although silica was not quantita tively evaluated, the use of ceramic-cup lysimeters did appear to result in elevated concentrations of silica in the water samples.

Hansen and Harris (1975) suggest that the sample collection rate of lysimeters should equal the pore-water drainage rate because the sample intake rate of a lysimeter could affect constituent concentrations in samples from a system that has solute concentrations that vary considerably in space. To determine variations in water chemistry caused by different sampling rates, two samples were collected from a lysimeter located in the Hulick Till Member. These samples were collected at 80 kPa (kilopascals) suction, the estimated most negative suction in the till, and at 20 kPa. Water chemistry was similar for the two samples (table 5).

Disturbance of flow patterns by suction-induced sam pling can result in samples that represent a larger soil volume than would be represented by a sample that reached the cup by way of undisturbed flow (Warrick and Amoozegar-Fard, 1977). However, tensiometers installed within 0.5 m of lysimeter cups showed no effect from suction-induced sampling, indicating that lysimeter samples in this study were drawn from a soil volume somewhat less than 0.5 m3 .

Because changes in pH might occur as a result of the degassing of carbon dioxide from water collected in the lysimeter, this possibility was investigated by installing a sample-sized lysimeter at the same depth as a full-sized lysimeter. The volume of the sample-sized lysimeter was similar to the volume of the sample collected, allowing no empty space above the sample within the lysimeter. Results from four pairs of samples collected during March 1984 indicated no differences in pH between samples from the two lysimeters. Although it is possible that degassing occurred as water was drawn into the lysimeters, the

potential for sample change due to degassing while in the lysimeters was considered negligible.

Lysimeters located in sand yielded insufficient amounts of water for water-chemistry analyses. To obtain sufficient sample volumes from the sand, samples were composited over a few days. Results of chemical analyses on uncomposited and composited water samples from a lysimeter located in the till (table 6) indicated no significant difference in major constituents between the two samples.

Claassen (1982, p. 32) reported that sampling with nitrogen affects sample chemistry less than sampling with air. Lysimeter samples for this study were collected using nitrogen gas to force samples out of lysimeters. For a more complete discussion of the representativeness of water samples collected from the unsaturated zone by using pressure-vacuum lysimeters refer to Peters and Healy (1988).

Five lysimeters were installed in borehole 585 (figs. 6 and 12), about 30 m east of trench 2, to define the water chemistry in undisturbed sediments. The lysimeters, referred to as "off-site" lysimeters, were located at depths from land surface of 1.2, 3.5, 6.7, 10.1, and 13.1 m in the Peoria Loess, Roxana Silt, Radnor Till Member, and Toulon Member.

Five lysimeters were installed in surficial sediments (within 3 m of land surface) near the center of the site to define the water chemistry in disturbed sediments. Three of the lysimeters were installed at depths of 0.3, 0.6, and 1.4 m in the cap of trench 2, and two were installed at depths of 0.5 and 0.8 m in the swale between trenches 2 and 3 (figs. 6 and 13).

Seven lysimeters were installed in the trench caps and swales directly above the tunnel to define the water chem istry in the disturbed sediments of the unsaturated zone above the trenches. The lysimeters were installed at depths of 0.4, 0.7, 1.0, 1.1, 1.3, 2.2, and 2.3 m in fill material, trench material, compacted clayey-silt cap, and in Peoria Loess (fig. 14). The 12 lysimeters in the disturbed sedi ments are referred to as "on-site, above-trench" lysimeters.

Thirteen lysimeters were installed from inside the tunnel into the Hulick Till Member and the Toulon Member within 2 m of the tunnel wall. These lysimeters, referred to as "on-site, below-trench" lysimeters, were spaced at dis tances of about 8 m along most of the tunnel. Five were installed along 12 m of the tunnel near the sloping Toulon Member/Hulick Till Member interface (fig. 14). Below- trench lysimeters were used to define the water chemistry in the unsaturated zone beneath the waste trenches.

During the period July 1982 through June 1984, pore-water samples were collected from lysimeters every 2 weeks and analyzed for specific conductance, pH, and tritium. Alkalinity was measured every 6 weeks, and major ions were determined quarterly. Generally, one pore-water sample from each lysimeter was analyzed for DOC. Gross alpha and beta scans were run annually on water samples


0

Borehole 585

COa:LLJ

LLJ O

ccD CO

a z<

6-

9H

LLJ CQ

XI 2^Q. LU Q

5-

I 8

- _ _ _ _5 8 5 -

A 585

A A

A

A A

Iff > | ; 1 1 ; ;

A

' A

^

1)

c

B

A

-----------

i A

A

i A

A

i ;; us i

A

A * A

PFHRIA 1 HFQQr C.Ur\IA 1 UC.Oo

ROXANA SILT

RADNOR TILL MEMBER

TOULON MEMBER

HULICK TILL MEMBER

CARBONDALE FORMATION

- GLASFORD FORMATION

EXPLANATIONGEOLOGIC CONTACT Dashed where gradational

585A PRESSURE-VACUUM LYSIMETER AND DESIGNATION

Figure 12. Lysimeter locations off-site (borehole 585).


METERS 240

239-

238-

237-

236

'52

EXPLANATION

GEOLOGIC CONTACT Dashed where gradational

PRESSURE-VACUUM LYSIMETER AND DESIGNATION

12 FEET

024 METERS

VERTICAL EXAGGERATION x 3

DATUM IS SEA LEVEL

Figure 13. Geologic section C-C showing on-site, above-trench lysimeter locations (modified from Healy and others, 1986, fig. 8). (See fig. 6 of this report for location of line of section.)

from each lysimeter. During dry periods and winter, pore- water samples could not be collected from all lysimeters.

Collection of Water Samples From the Saturated Zone

Water-chemistry data collected from seven wells by Foster and Erickson (1980) and Foster and others (1984a) were used to define the chemistry of local ground water. The wells were selected because they were near the lysim eter locations (fig. 6), their water-chemistry data were relatively complete, and the wells were screened in geologic materials similar to the materials surrounding the lysime ters. Of the seven wells, two (502, 505) are legally considered "off-site" wells. For the purpose of this report, wells 502, 524, and 527 also are considered off-site wells on the basis of their relative distances from the trenches.

Wells were drilled using hollow-stem augers, cased in steel, screened in stainless steel, and sealed with bentonite and portland-cement-based grout. From 1978 through 1982, water samples were collected either once or twice annually and analyzed for major ions. Tritium concentra

tions were measured quarterly in the seven wells in 1982 and 1983 (Foster and others, 1984a). Prior to sampling, wells were purged of three casing volumes of water or bailed until dry, then allowed to recover. Water samples were collected by using a bailer or a peristaltic pump.

Interpretive Techniques

Graphs, statistics, and geochemical models were used to interpret the spatial heterogeneity of pore-water chemis try in the unsaturated zone. Graphs included trilinear diagrams, fence diagrams, and two-dimensional graphs. Trilinear diagrams (Piper, 1944) were used to show the differences in pore-water chemistry between different lithologic units. Graphs were used to compare concentrations of different constituents, relate concentrations of single constituents to a specific time frame, and show relations between constituent concentrations and lithology.

Descriptive statistics, correlation coefficients, time trends, and analysis of variance were computed using


22550 100 FEET

0 10 20 30 METERS


EXPLANATION

GLASFORD FORMATION Compacted Layer (not to scale)

I_1_ J TRENCH AND DESIGNATION

GEOLOGIC CONTACT

...T... WATER TABLE

89 PRESSURE-VACUUM LYSIMETER AND DESIGNATION Vertical position of tunnel lysimeters approximate.

Figure 14. Geologic section A-A' showing lysimeter locations in trench caps and in the tunnel. (See fig. 6 of this report for location of line of section A-A',)

P-STAT (Buhler and others, 1983) and SAS (SAS Institute, Inc., 1982) data-management and statistical-analysis com puter software. The programs computed correlations between concentrations of various constituents and between concentrations and time. In all statistical analyses, analyti cal values less than detection limits were assumed to follow a uniform distribution between zero and the detection limit (D.A. Rickert, written commun., 1985).

Analysis of variance (ANOVA) was used to deter mine the relative importance of factors influencing constit uent concentrations. A two-by-six factorial design was used to determine simultaneously the effects of two factors on the concentrations of constituents (for example, on-site Hulick Till Member with respect to off-site Roxana Silt).

Two geochemical models were used. The first, WATEQF (Plummer and others, 1976), employs chemical speciation to calculate the saturation indices (SI) of aqueous solutions with respect to solids. The second, BALANCE

(Parkhurst and others, 1982), calculates the mass transfer of constituents entering or leaving the aqueous phase to account for observed changes in the chemical composition of water. Mass-transfer calculations (BALANCE) com bined with speciation calculations (WATEQF) are useful for defining chemical reactions that may occur in the geologic medium.

Simulations of chemical equilibria by WATEQF and BALANCE are dependent on pH. A sensitivity analysis to determine the magnitude of possible error in pH measure ments was made by comparing calculated partial pressures of carbon dioxide (PCO2) determined by WATEQF for lysimeters at borehole 585 to pCO2's measured from similar depths from three boreholes (a, b,, and c) near borehole 585 (figs. 6 and 8) (Striegl, 1988). Inputs of pH to the WATEQF model from the borehole 585 lysimeters were changed until calculated pCO2 's equaled measured pCO2 's. The pH change that was required to attain agreement


between calculated and measured pCO2 's averaged 0.2 pH units in the Toulon Member and the Hulick Till Member, -0.7 in the Roxana Silt, -0.5 in the Radnor Till Member, and 0.9 in the Peoria Loess. The average decrease in pH required to match calculated and measured pCO2 's was 0.46. Possible reasons for this pH discrep ancy include (1) measured pCO2 's from boreholes a, b, and c may not accurately represent PCO2 concentrations in borehole 585; (2) the probability that equilibrium conditions do not exist in major portions of the unsaturated zone; and (3) the effect of degassing of the sample as it is drawn into the lysimeter. Additionally, possible lasting effects of the leaching of ceramic cups with hydrochloric acid (Suarez, 1986) could cause the measured pH's to be lower than in situ pH's. The decreased modeled pH's caused lowered saturation indices (SI= log IAP/K, where IAP= the activity product of aqueous ions produced by a reaction, and K=th& chemical-equilibrium constant for the reaction) for both calcite and dolomite, an average of 0.35 and 0.60, respectively. However, in only a few instances were these changes large enough to cause them to fall below saturation. Saturation indices for aragonite and montmorillonite were not substantially changed.

PROPERTIES OF GEOLOGIC MATERIALS

Particle-size distribution, surface area, bulk density, and bulk porosity of geologic materials from the various lithologic units are listed in table 7. Particle-size distribu tions of the Hulick Till Member and the Radnor Till Member of the Glasford Formation were similar, although sand content in the Hulick Till Member was slightly higher. Peoria Loess and Roxana Silt had the highest percentage of silt. Surface areas were highest in the Roxana Silt, the Hulick Till Member, and the Radnor Till Member, followed by the Peoria Loess. Bulk density was least in the Peoria Loess and the Roxana Silt, greatest in the Radnor Till Member and the Hulick Till Member, and most variable in the trench material. Porosity trends were inversely related to bulk-density trends.

Mean values of pH, cation-exchange capacity, con centration of calcium and magnesium, percentage of iron, and percentage of organic matter are presented in table 8. Values of pH for geologic materials averaged 7.5. The total range of pH was from 6.2 to 8.4 (Piciulo and others, 1982). The lowest pH values were in the Hulick Till Member, and the highest values were in the Toulon Member of the Glasford Formation.

Mean cation-exchange capacities for lithologic units ranged from 4.4 meq/100 g (milliequivalents per 100 grams) in the Toulon Member to 20.2 meq/100 g in the Radnor Till Member. Cation-exchange capacities are a significant factor when determining the exchangeability of radionuclides (Piciulo and others, 1982).

The most abundant of the exchangeable ions listed in table 8 were calcium, having mean bulk-sample concentra tions of 17 to greater than 190 meq/100 g, and magnesium, having mean concentrations of 3.6 to greater than 73 meq/100 g. Concentrations of exchangeable ions in the geologic materials indicate their relative availability to pore water.

Iron content (as percentage of fine sands by weight) is an indicator of the potential of the medium for adsorbing chemical constituents (Jenne, 1977; Means and others, 1978). Also, iron oxide precipitates may interact with electronegative clay minerals and adsorb radionuclides (Reesman and others, 1975, p. 12-5). The highest iron values were found in the Radnor Till Member, which is visibly mottled with oxidized iron, and the lowest values were in the Toulon Member.

Organic content of geologic materials can affect cation exchange, the sorptive capacity of the sediment- water system, and water movement in the materials (Brady, 1974, p. 150). Percentage of organic matter commonly varies from a trace to 15 percent (Brady, 1974, p. 154). Mean values of percentage of organic matter in unconsolidated deposits at the Sheffield site ranged from 0.1 to 2.1. The highest percentage of organic matter was in the Peoria Loess, where modern soil is developing.

Mineralogic properties of the lithologic units are shown in table 9. The matrix (in the petrographic analysis section), which is the portion of sample that is unidentifi able because of small size, probably consists of clay minerals, silica, and feldspars. Aluminosilicate clays are derived from feldspars.

The buffering capacity of geologic materials can be inferred from carbonate content. Peoria Loess had the highest bulk-carbonate content, and the Roxana Silt had the lowest. The Hulick Till Member had the highest calcite-to- dolomite ratios in the silt- and clay-size fractions.

Clay-sized particles accounted for 6-30 percent of the geologic materials (table 7). Minerals in the clay-sized fraction included montmorillonite, illite, and kaolinite plus chlorite. Montmorillonite, a sodium-containing aluminosilicate of the smectite group, ranged from 82 percent of the clay-mineral portion of the Roxana Silt to only 17 percent of the clay-mineral portion of the Toulon Member (table 9). Illite ranged from 62 percent of the clay minerals in the Toulon Member to 10 percent in the Roxana Silt. Kaolinite plus chlorite ranged from 27 percent in the Hulick Till Member to 8 percent in the Roxana Silt.

Gross alpha and beta radiation did not exceed detec tion limits in any core samples of geologic materials. Detection limits were less than 1 count per hour for alpha activity and about 1 count per minute for beta activity.

Results of gamma-spectral analyses of 245 core samples obtained from above the tunnel were virtually identical to those determined for background samples. The highest potassium-40 concentrations measured were 7 pCi/g

Properties of Geologic Materials 17

(picocuries per gram), followed by radium-226 at 1 pCi/g. Trace amounts of radium-228, thorium-228, and thorium- 234 also were detected. Concentrations refer to activity of the bulk sample and include the pore water.

CHEMISTRY OF WATER SAMPLES

The chemistry of water in the unsaturated zone is a function of the initial infiltrate chemistry, the pathway the water has taken between infiltration and the sampling points, and the rate of the water movement along the path. Chemical analyses of pore-water samples indicated bicar bonate (reported as CaCO3 (calcium carbonate) alkalinity), calcium, magnesium, sodium, sulfate, silica, chloride, iron, and zinc were the primary inorganic constituents. Samples also were analyzed for specific conductance, pH, DOC, gross alpha and beta radiation, and tritium. Table 14 provides physical characteristics of the water-chemistry sampling sites. Results of analyses for inorganic constitu ents, DOC, and tritium also are shown in tables 15 through 19. Table 14 aids interpretation of tables 15 through 19 and also of table 20 (regarding saturated-zone water samples). The concentrations listed in tables 16 through 19 are for samples collected after an initial stabilization period follow ing lysimeter installation. Chemical concentrations for some samples collected during the stabilization period were influenced by water used in grout and backfill slurries. Those concentrations were deleted from the data set. The stabilization period at borehole 585, a 150-rnm-diameter borehole that contains five lysimeters, was about twice as long (about 0-4 months) as it was at 25-rnm-diameter boreholes that contained only one lysimeter (about 0-2 months).

Precipitation

The specific conductance of precipitation ranged from less than 10 to 70 jxS/cin (microsiemens per centime ter at 25°C) and averaged 28 jxS/cm (table 15). Values for pH ranged from 3.8 to 7.5. The average hydrogen-ion concentration, expressed as pH, was 4.6. The ionic com position of precipitation was calcium zinc sulfate (fig. 15). The average zinc concentration in precipitation was 1,300 |xg/L; this average was higher than in pore water from the unsaturated zone (averaged 340 jxg/L) or in ground water (averaged 240 jxg/L). Elevated concentrations of zinc have previously been noted in precipitation in Illinois (D.F. Gatz, Illinois State Water Survey, oral cornmun., 1984). The source of elevated concentrations of zinc in precipita tion is not known. Gross-alpha and gross-beta radiation did not exceed detection limits in any precipitation or subsur face water samples. Tritium concentrations in precipitation were 0.2 nCi/L.

Unsaturated-Zone Pore Water

Undisturbed Unsaturated Zone, Borehole 585

Water samples from five depths in borehole 585 were analyzed to evaluate conditions in an undisturbed area (table 16; mean values in table 10). Values for pH ranged from 7.1 to 8.4 and averaged 7.5. The lowest average pH was 7.4 in the Toulon Member of the Glasford Formation, and the highest was 7.7 in the Peoria Loess and the Roxana Silt. Specific conductance ranged from 815 to 2,250 |JL,S/cm and averaged 1,200 jxS/cm. Specific conductances varied most at lysimeter 585D in the Roxana Silt.

The ionic composition of water was calcium sulfate in the Peoria Loess, sodium bicarbonate sulfate in the Roxana Silt, and calcium magnesium bicarbonate in the Radnor Till Member of the Glasford Formation and the Toulon Member (fig. 15). Alkalinity averaged 500 mg/L (milligrams per liter) as CaCO3 and had a standard deviation of 100 mg/L. Alkalinities are virtually equal to bicarbonate for the range of pH of all samples. Bicarbonate was the predominant anion in all water samples except for one sample from the Peoria Loess. About 32 percent of anion equivalent weight was bicarbonate in the Peoria Loess, and 66 percent was bicarbonate in the Toulon Member. Sulfate was the second most predominant anion and had the highest concentrations in water from the Peoria Loess and the Roxana Silt.

The milliequivalent ratio of calcium to magnesium varied with depth and geologic material, having the lowest ratio (1.16) in the Toulon Member, and the highest ratio (1.50) in the Roxana Silt (as calculated from data in table 16). Sodium concentrations averaged 49 mg/L and had a standard deviation of 26 mg/L, except in the Roxana Silt where they averaged 200 mg/L and had a standard deviation of 45 mg/L.

Silica concentrations were relatively constant throughout the profile and averaged 70 mg/L. Chloride concentrations averaged 8.4 mg/L, having the highest concentration, 43 mg/L, in the shallowest lysimeter location (Peoria Loess); the next highest concentration, 25 mg/L, was in the deepest lysimeter location (Toulon Member). Zinc concentrations averaged 30 jxg/L, and concentrations increased slightly with depth. High sulfate and chloride concentrations in the Peoria Loess do not appear to be representative of typical conditions elsewhere off-site and on-site and may represent localized conditions.

DOC concentrations ranged from 2.2 to 3.7 mg/L and averaged 2.9 mg/L at off-site lysimeters; background con centrations are considered to be approximately 3 mg/L. Tritium was the only radionuclide detected. Concentrations of tritium ranged from 0.2 to 6.9 nCi/L. The average off-site pore-water tritium concentration was 0.7 nCi/L and was 0.3 nCi/L in the Peoria Loess and 1.2 nCi/L in the Toulon Member. Water-quality criteria (U.S. Environmen tal Protection Agency, 1976) include a tentative limit of 20


Ca

CATIONS ANIONS

PERCENTAGE OF TOTAL MILLIEQUIVALENTS PER LITER

EXPLANATION

BOREHOLE SITE 585 AND GEOLOGIC UNIT Symbol size represents relative specific- conductance value

MEAN SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER AT 25 DEGREES CELSIUS

*E

DoAC

OB

Peoria Loess 1,100

RoxanaSilt 1,410

Radnor Till Member of the Glasford Formation 1,020

Toulon Member of the Glasford Formation 1,160; 1,240

p PRECIPITATION 28

A SITE-Cations or anions

Figure 15. Ionic composition of water collected from off-site lysimeters (borehole 585) and precipitation.

Chemistry of Water Samples 19

nCi/L tritium for drinking water. The U.S. Nuclear Regu latory Commission's (1975) maximum permissible concen tration for tritium in effluent released to uncontrolled areas is 3,000 nCi/L.

Disturbed Unsaturated Zone, Above Trench

Results of chemical analyses of water samples col lected from 25 on-site lysimeters, including 12 above- trench and 13 below-trench lysimeters, are listed in tables 17 and 18. Mean concentrations of constituent are presented in table 11.

Specific conductance of pore water from on-site, above-trench lysimeters (table 17) ranged from 480 to 2,200 |xS/cm and averaged 1,100 /xS/cm. Lowest specific con ductances were for water samples from the Peoria Loess and represent recently infiltrated precipitation. The pH averaged 7.4 and ranged from 6.8 to 8.7.

The ionic composition of water in the above-trench sediments, within at least 0.3 m of land surface, was calcium bicarbonate; below that depth the water generally changed to calcium magnesium bicarbonate. Alkalinity values averaged 460 mg/L as CaCO3 ; the minimum was 270 mg/L, and the maximum was 760 mg/L. Bicarbonate was the predominant anion in all water samples except one sample from lysimeter 39. Sulfate values were nearly as dominant as bicarbonate in lysimeters 38 and 87 (clayey-silt cap, figs. 13 and 14) and 39 (fill material, fig. 13). Percentage of anionic composition of samples from lysim eters ranged from 93 percent bicarbonate in water from lysimeters 40 and 51 (Peoria Loess) to 53 percent sulfate in water from lysimeter 39 (fill material, fig. 16). Percentage of compositions remained relatively constant over time for individual lysimeters.

Calcium was the predominant cation in all above- trench water samples except lysimeter 52 (fill material). Magnesium was the second most abundant cation in all above-trench pore-water samples except lysimeter 52, where it was most abundant. Equivalent-weight ratios of calcium to magnesium ranged from 0.79 to 2.17 (computed from data in table 16); ratios for a 1:1 dolomite (equal parts calcium and magnesium) are about 1.65 (Reesman and others, 1975, p. 12-7). Sodium concentrations ranged from 1.4 to 22 mg/L and averaged 13 mg/L.

Silica concentrations ranged from 3.4 to 74 mg/L and averaged 32 mg/L; water samples from lysimeter 51 (Peoria Loess) averaged only 5.8 mg/L. Lower concentrations of other constituents also were reported in samples collected from lysimeter 51.

Chloride concentrations ranged from 0.1 to 72 mg/L and averaged 25 mg/L. Zinc concentrations averaged 140 fxg/L.

DOC concentrations ranged from 2.8 to 63 mg/L and had a mean of 15 mg/L. The highest concentration was in water from lysimeter 88, which is located just below the

clayey-silt cap in trench 2. The mean concentration for all water samples, excluding lysimeter 88 samples, was 8.5 mg/L.

Tritium concentrations ranged from 0.2 to 1,380 nCi/L and had a mean value of 140 nCi/L and a median value of 11 nCi/L. The highest average concentration (1,270 nCi/L) and the highest individual concentrations were in water samples from lysimeter 88. Excluding the uncharacteristically high tritium concentrations of water samples from lysimeter 88, tritium concentrations in water from on-site, above-trench lysimeters averaged 22 nCi/L. Water from lysimeter 52, located in the fill material and nearest land surface, had the lowest mean concentration (0.5 nCi/L).

Tritium concentrations at above-trench lysimeters varied seasonally. The highest concentrations occurred (with a slight lag time) during dry periods in the late summer and early fall when samples were less diluted by infiltrating precipitation and when evapotranspiration rates were highest (fig. 17).

Tritium concentrations in water from soil cores col lected at the points of lysimeter-cup installation ranged from 0.2 to 1,230 nCi/L and averaged 68 nCi/L in the above- trench samples (table 19); the median concentration was 2.1 nCi/L. Tritium concentrations in pore water from the cores increased with depth and with proximity to trenches. The tritium concentrations in the cores generally were similar to the initial concentrations in pore water collected from lysimeters installed at the same locations.

Disturbed Unsaturated Zone, Below Trench

Specific conductances ranged from 250 to 3,500 |xS/cm (table 18), averaged 1,060 /xS/cm, and had a standard deviation of 440 /xS/cm. The highest and most variable specific-conductance values were in water samples from the Toulon Member. The highest values in the Toulon Member (most notably at lysimeter 64) were commonly associated with the highest pH values, and alkalinity and DOC concentrations. Samples from lysimeter 96, located in the Hulick Till Member of the Glasford Formation near the interface with the Toulon Member, were the most dilute (figs. 7 and 18). The interface intersects the tunnel as the Hulick Till Member dips toward the northeast. Specific conductances decreased with increased distance of the lysimeters from the trenches.

The average pH was 7.5, minimum pH was 6.9, and maximum pH was 9.2. Highest pH values were in samples from lysimeters located in the Toulon Member.

The ionic composition of water generally was cal cium magnesium bicarbonate. Samples from lysimeter 68, located in the Hulick Till Member near the Toulon Mem- ber/Hulick Till Member (sand/till) interface, had slightly higher sulfate (calcium magnesium sulfate) and chloride


ca 'o ^o ' <v v ciCATIONS ANIONS


EXPLANATION

SITE AND GEOLOGIC UNIT Symbol size represents relative specific-conductance value


A 87;38

Q39

O52

D9V.88

*89;40

* 51

* 87

Figure 16.

Clayey-silt cap 1,310; 1,130

Fill material 1,330

Fill material 875

Trench material 1,370; 1,030

Peoria Loess 974; 804

Peoria Loess 629

SITE Cations or anions

Ionic composition of pore water collected from on-site, above-trench lysimeters.


3s I i" <L I I I Si

$#

TR

ITIU

M C

ON

CE

NT

RA

TIO

N A

T LY

SIM

ETE

R 3

8,

IS

IN

NA

NO

CU

RIE

S

PER

LIT

ER

(/}n

fD

o>

o>i-

h

on5"

o

O

fD

3 o o

c 3"

OK)

0>

IT 3

, _

t/i

c"2

.

ss ^.

{u ,

3

3

CL

O

on

C

L 2

.

3 S

3 o'

is on

Q.

ni

x-v

= on

to

U>

O i\ Ul

$.0

O cr i fD O

EV

AP

OT

RA

NS

PIR

AT

ION

, IN

MIL

LIM

ET

ER

S O

F W

ATE

R

Ol

01N

J 01

CM

OO

l oo

oen o

Q.

co

So

_

*Oon

0

0

sr

CM

CO o

io2I

w

w

Ol

OD

OB

10

>

o-<

^J

m

r >

Co

r^

OC

w

~*

(/)O

^

> ^

enO en

Oi

O) o

00 o

o

o

TR

ITIU

M C

ON

CE

NT

RA

TIO

N A

T LY

SIM

ETE

R 89,

IN N

AN

OC

UR

IES

PE

R L

ITE

R

SO

IL S

ATU

RA

TIO

N,

IN P

ERC

ENT

82

<§> Ca 'O ^0 <V V Cl

CATIONS ANIONS


68; 62

D 63

D 96

83; 82

61; 81; 84

68

EXPLANATION

SITE AND LOCATION RELATIVE TO INTERFACE WITH TOULON MEMBER OF THE GLASFORD FORMATION-Symbol size represents relative specific-conductance value

Near interface

Near interface

Near interface

Away from interface

Away from interface



1,060; 1,000

978

407

1,120; 1,030

954;938; 826

Figure 18. Ionic composition of pore water collected from on-site, below-trench lysimeters in the Hulick Till Member of the Glasford Formation.


concentrations than those away from the interface and varied more chemically (fig. 18).

Alkalinity ranged from 87 to 820 mg/L and had a mean value of 410 mg/L. Water samples from lysimeter 96 had the lowest mean alkalinities. The highest mean- alkalinity values were for samples from lysimeters 64, 82, and 83. Lysimeter 64, installed in sand near the sand/till interface below trench 2, had the highest alkalinity value. Lysimeters 82 and 83 are located below trench 11. Bicar bonate was the predominant anion in all samples except lysimeter 68. Bicarbonate and sulfate were present in nearly equivalent concentrations in samples from lysimeter 68 (Hulick Till Member).

Calcium and magnesium were the most abundant cations in water samples. Sodium concentrations ranged from 8.9 to 28 mg/L in all below-trench water samples except for samples from lysimeters 26, 62, and 64, where concentrations ranged from 32 to 140 mg/L. Sodium concentrations in the Hulick Till Member near the sloping sand/till interface averaged 35 mg/L, and those in the Hulick Till Member away from the interface averaged 16 mg/L.

Silica concentrations in water samples ranged from 34 to 81 mg/L at all lysimeter locations except lysimeter 64 (Toulon Member); the single measurement of silica concen tration at that location was 120 mg/L. Chloride concentra tions ranged from 3.6 to 73 mg/L. The highest average concentration was from lysimeter 65 in the Toulon Mem ber. Chloride concentrations averaged 26 mg/L in water samples from lysimeters near the sand/till interface com pared to 10.9 mg/L in samples collected away from the interface. Zinc concentrations ranged from 12 to 9,700 |u,g/L and had an average value of 560 |u,g/L and a median value of 140 |mg/L.

DOC concentrations ranged from 5.8 to 70 mg/L and had a mean concentration of 32 mg/L. Highest concentra tions were in water samples from lysimeters 62, 64, 65, and 96, near the sand/till interface. Concentrations of DOC decreased as distance from the trenches increased.

Tritium concentrations in below-trench water samples ranged from 0.2 to 450 nCi/L and had a mean value of 70 nCi/L and a median value of 28 nCi/L. Average tritium concentrations near the interface (86 nCi/L) were higher than concentrations away from the interface (60 nCi/L). Pore-water tritium concentrations in samples from some below-trench lysimeters varied seasonally (fig. 19), and highest concentrations occurred in the spring (wetter) months.

High tritium concentrations in below-trench water samples in the spring may be due to freshwater infiltrating the trenches and flushing tritium from the waste materials, or due to water that had been in contact with the waste since the previous spring being flushed from the trenches. Tritium concentrations in water samples from lysimeters 62, 65, and 82 increased with time (18 months) by factors of about 4.5

to 9 (fig. 20). The relatively sudden increases in tritium concentrations at lysimeters 62 and 65 appear to be related to the simultaneous occurrence of a large rainfall (124 mm) during July 29-30, 1983, and the development of several sinkholes in overlying trench caps. Tritium concentrations remained high after that time.

Tritium and DOC concentrations in water samples from below-trench lysimeters had a moderate positive correlation (correlation coefficient of 0.55), which indicates an association between the sources of tritium and organic carbon (most probably the waste containers in the trenches).

Tritium concentrations in water from soil cores ranged from 0.4 to 170 nCi/L and averaged 44 nCi/L in the below-trench samples (table 19); the median concentration was 34 nCi/L. Tritium concentrations in the below- trench cores were, for the most part, higher in sand cores than in the till cores. Concentrations varied most near the sloping interface between the Toulon Member and the Hulick Till Member. In cores collected from the tunnel, concentrations of tritium in the tills often decreased with distance from the tunnel.

Saturated-Zone Water

Chemical analyses of water collected from the obser vation wells were used to define ground-water chemistry near the lysimeters (fig. 6 and table 20). Specific conduc tances of ground water averaged 1,140 |u,S/cm and ranged from 328 to 2,130 |mS/cm. The pH ranged from 6.2 to 9.0 and averaged 7.0.

The ionic composition of water was magnesium bicarbonate in all wells except well 502, where it was sodium magnesium bicarbonate. Sulfate concentrations in water samples from well 507 were higher than in samples from other wells (fig. 21).

Calcium and magnesium were the predominant cat ions. The mean calcium concentration was 92 mg/L; the mean magnesium concentration was 85 mg/L. Sodium concentrations averaged 30 mg/L. In well 502 (Hulick Till Member, off-site) water samples, sodium was the predom inant cation, having an average concentration of 61 mg/L.

Alkalinity ranged from 36 to 1,150 mg/L and aver aged 490 mg/L. Bicarbonate was the predominant anion in all samples. Bicarbonate equivalents composed 65 to 85 percent of the anions in all samples except the samples from well 507 (Hulick Till Member, on-site) where bicarbonate composed 52 percent of the anions.

Silica concentrations ranged from 0.9 to 23 mg/L and averaged 12 mg/L. Chloride concentrations ranged from 1.8 to 37 mg/L and averaged 8.5 mg/L; lowest concentrations were from wells 502, 524, and 527, the wells that are located farthest off-site. Highest chloride concentrations in ground water were in samples from wells 505, 523, and


a: LJ

a: LJQ_

toUJ

O O

bJ O:zO O

20

15

10

~iIIIIiIIIIIIIIIIr LYSIMETER 61- HULICK TILL MEMBER

(GLASFORD FORMATION)

8

6

4:zfo

0

50

40

30

20

10

I I T I I

LYSIMETER 84 HULICK TILL MEMBER

LYSIMETER 83- HULICK TILL MEMBER

NDJFMAMJJASONDJFMAM1982 1983 1984

Figure 19. Seasonal trends in tritium concentrations in pore water from three below-trench lysimeters from November 1982 through May 1984.


800

_j 600

LJ t/)

or) ou

200

1 I I I I I I I I I I I I I T

LYSIMETER 62-HULICK TILL MEMBER

LYSIMETER 65-TOULON MEMBER

I I

GLASFORD FORMATION

LYSIMETER 82-HULICK TILL MEMBER

NDJFMAMJJASOND.JFMAM 1982 | 1983 I 1984

Figure 20. Tritium concentrations in pore water from three below-trench lysimeters from November 1982 through May 1984.

528, which are located adjacent to trench 11. Zinc concen trations ranged from less than 50 to 1,100 jxg/L and averaged 240 |xg/L.

DOC concentrations were measured in water samples collected from wells 502 and 528. Concentrations in these wells were near background levels; DOC concentrations ranged from 1.5 to 2.8 mg/L and had a mean of 2.3 mg/L.

Tritium concentrations averaged 38 nCi/L, having a minimum of 0.2 nCi/L and a maximum of 170 nCi/L. The lowest concentrations were in water from wells 502, 524, and 527, located farthest from trenches (off-site wells). The highest concentrations were in water from well 523 located adjacent to trench 11. Tritium concentrations in ground water were significantly different between on-site and off-site wells. On-site concentrations averaged 81 nCi/L, and off-site concentrations averaged 2.9 nCi/L.

EFFECTS OF RADIOACTIVE-WASTE DISPOSAL ON WATER CHEMISTRY IN THE UNSATURATED ZONE

Affected Constituents

Burial of low-level radioactive waste in the unsaturated zone has the potential to alter the chemistry of pore

water that percolates to the aquifer. Excavation during waste-trench construction removes geologic material that naturally interacts with water to neutralize precipitation, provides surfaces for chemical adsorption and ion exchange, and contributes ions to solution through solution- recrystallization reactions. Replacement of those materials with low-level radioactive waste provides a source that can contribute radionuclides, metals, and various organic sol vents and petrochemicals to the ground-water system. Compaction of trench-cap materials over waste materials can inhibit communication between the unsaturated zone and the atmosphere, creating localized redox conditions that can mobilize some waste types. The failure of trench caps (Gray and McGovern, 1986) can provide pathways for channelized flow of surface runoff through waste materials. The sections that follow discuss the hydrogeochemical processes that determine the occurrence of dominant ions in the unsaturated zone, apparent effects of waste disposal on those processes, and chemicals present in the pore water that have a source at the waste.

Carbonate Minerals

Reactions of water and carbon dioxide with carbonate minerals largely determine the concentrations of bicarbon ate, calcium, and magnesium ions in solution. Important carbonate-dissolution reactions that occur in various units in


Ca ~0 ^O V V Cl

CATIONS AN IONS


EXPLANATION

1 507; 523; 505; 528

& 527

A 502

A 524

507

SITE AND GEOLOGIC UNIT Symbol size represents relative specific-conductance value

Hulick Till Member of the Glasford Formation, on-site

Roxana Silt, off-site

Hulick Till Member, off-site

Hulick Till Member, off-site



1,630; 1,480; 1,350; 1,250

946

828

414

Figure 21. Ionic composition of water collected from the saturated zone.

the unsaturated zone at the Sheffield site include congruent dissolution of calcite (1) and dolomite (2), which contribute HCO3 ~ (aq) , Ca+2(aq) , and Mg+2(aq) ions to solution; and

incongruent dissolution of dolomite to calcite (3), whichcontributes a Mg (aq) ion to solution and precipitates a Ca+2

(aq)

(aq)

ion to calcite.

Effects of Radioactive-Waste Disposal on Water Chemistry in the Unsaturated Zone 27

CaC03(s) +H20(1) +C02(aq) =Ca+2(aq) +2HC03 (aq) (1)

CaMg(C03)2(s) +2H20(1) +2C02(aq) =

Ca (aq) + Mg (aq)

CaMg(C03)2(s) +Ca+2(aq) =Mg+2

3 (aq)

(aq) +2CaC03(s)

(2)

(3)

Sufficient amounts of carbonate minerals are present in the unsaturated zone for reactions 1 to 3 to be maintained at or near chemical equilibrium. Therefore, the mass transfer of bicarbonate, calcium, and magnesium to and from solution depends on the PCO2 in the unsaturated-zone atmosphere. At borehole 585, average PCO2 increases from about 0.035 percent by volume at the land surface to about 3.9 percent at a depth of 11 m (Striegl and Ruhl, 1986). The largest annual variation in PCO2 , from about 1.2 to 5 percent, is found in the near-surface root zone where annual peak PCO2 coincides with peak periods of soil- microorganism and root respiration during late summer (Thorstenson and others, 1983, p. 324-325; Suarez, 1982, p. 303).

Saturation indices (SI) were determined using the geochemical model WATEQF and the equilibrium con stants shown in table 12. The SI (table 13) indicated that water samples from nearly all sites were supersaturated (SI greater than zero) with calcite and dolomite. Pore water from lysimeter 96 was undersaturated for three of four samples with respect to both calcite and dolomite. Highest SI generally were found near the surface both on-site and off-site. Lowest SI were found in the trench material on-site and just below the Roxana Silt in the Radnor Till Member of the Glasford Formation off-site (table 13). Greatest variability in the SI was in the Peoria Loess on-site and in the Roxana Silt off-site. Most samples were more saturated with dolomite than with calcite (fig. 22). This imbalance could be due to (1) incongruent dissolution of dolomite, (2) preferential exchange of calcium for magnesium in cation- exchange reactions with clay minerals, (3) preferential precipitation of calcite with respect to dolomite (Drever, 1982; Thorstenson and others, 1979; Henderson, 1984), or (4) the carbonate mineralogy of the geologic materials (table 9).

Calculations made using the BALANCE model indi cated the possibility of calcite precipitation from supersat urated water in the fill material, the clayey-silt cap, and the Toulon Member of the Glasford Formation. Microscopic examination indicated that sand grains from upper parts of the Toulon Member at borehole 585 had secondary deposits of calcite. Calcium-to-magnesium ratios in the pore water decreased with depth in the unit near that location.

Rates of calcite dissolution are relatively rapid, even for extremely small ratios of calcite surface area to water volume; calcite dissolution is rapid relative to dolomite dissolution (Plummer and others, 1978). At the Sheffield site, Ca+2(aq) concentrations increased more rapidly in the first meter of depth than did Mg+2(aq) , even though dolo-

t.50

LJ 1.25Q

t.OO

0.75

LJt 0.50 O

O0.25

I I OBSERVED VALUE

LINE OF EQUAL SATURATION FOR CALCITE AND DOLOMITE

0 0.5 1.0 1.5 2.0 2.5

DOLOMITE SATURATION INDEX

Figure 22. Relation of dolomite saturation index to calcite saturation index.

mite was more abundant than calcite in those geologic materials (tables 9, 16-18, and 20).

Dissolution of carbonate minerals is more extensive at a low pH than at a high pH. In turn, the ions produced by the dissolution of carbonates buffer the pH of the water that contacts the carbonate minerals. Water that infiltrated the unsaturated zone increased from an average pH of 4.6 in precipitation to an average pH of 7.9 in the first 0.3m from the land surface. Below that depth, the pH of water in the unsaturated zone averaged 7.5 and remained between 6.8 and 9.2.

Pore-water pH was highest and most varied in the Toulon Member. High pH and large variances in pH can result from CO2(aq) degassing from pore water collected in lysimeters. Degassing occurs more rapidly than precipita tion of carbonates and can cause increases in pH and supersaturation of water with respect to carbonate minerals (Freeze and Cherry, 1979, p. 255). It is likely that the effects of CO2(aq) degassing would be most noticed for samples collected from the Toulon Member, where the average PCO2 is highest. Another possible reason for higher and more variable pH's in the Toulon Member could be relatively rapid water movement from the trenches through the sand of the Toulon Member.

The equilibrium chemistry of carbonate minerals also can be affected by cation-exchange processes. The Hoffmeister series, which predicts the affinity of cations to sediment surfaces in the order of Ca+2>Mg+2>Na+ (Stumm and Morgan, 1981, p. 645; Brady, 1974, p. 75), favors Ca+2 and Mg+2 to adsorb to surfaces and Na+ to move into solution as follows:


4ExNa+Ca2+ +Mg2+^4Na+ +ExCa+ExMg.

Increased Na+ concentrations coupled with decreased Ca+2(aq) and Mg +2(aq) concentrations (fig. 23) are indica tive of cation exchange (Henderson, 1984, p. 13-15). In general, high concentrations of Na+ (aq) were present in geologic units where the montmorillonite content of the clay-mineral fraction was high (fig. 24). As much as 250 mg/L Na+ was measured in pore water collected from the Roxana Silt, where the montmorillonite content was highest (82 percent).

Ratios of Ca+2(aq) to Mg +2(aq) generally were related directly to the calcium content of the geologic materials from which pore water was collected (fig. 25). Both Ca/Mg ratios and the content of calcium in the soil were highest in the Peoria Loess. The ratio decreases considerably from the surficial deposits to the Toulon Member both off-site and on-site (figs. 23 and 25). The pronounced decrease in theCa+2

(aq),-to-Mg + 2

(aq) ratio in the Toulon Member on-site ispossibly induced by the presence of the tunnel. The partial pressure of CO2 in the air that is mechanically circulated through the tunnel is about two orders of magnitude less than the PCO2 that is naturally found in the Toulon Member. Mixture of that air into the unsaturated zone that surrounds the tunnel can cause extensive crystallization of calcite as a secondary mineral on grain surfaces. Dolomite does not readily recrystallize at the temperatures found in the unsat urated zone (Hosteller, 1964, p. 34-49); hence, Mg +2(aq) concentrations remain nearly constant from the trench material to the Toulon Member. Also, more cation exchange might take place in the Roxana Silt (SI= 1.04 for calcite and 1.98 for dolomite), which is present off-site only, resulting in decreased dissolved calcium and magne sium concentrations in the off-site Toulon Member.

Sulfate

Sulfate is the second most predominant anion found in the unsaturated zone at the Sheffield site. The possible sources of sulfate (SO4~ 2(aq)) in unsaturated-zone pore water include fragments of sulfate-rich bedrock incorpo rated in the till during its deposition; the oxidation of organic sulfur, which was deposited in the till after glacial- ice erosion of organic-rich bedrock; and the oxidation of the sulfide minerals pyrite and marcasite.

The availability of sulfate in the till from fragments of sulfate-rich bedrock is minimal (0.008 to 0.056 meq/100 g in dry soil). Furthermore, there is no apparent correlation between sulfate available in the various geologic units and the pore-water sulfate concentrations in those units. The oxidation of organic sulfur as a source for pore-water sulfate concentrations (Hendry and others, 1986) is possible. How ever, sulfate concentrations generally cannot be correlated with percentage of organic matter in the sediments. Thus,

the apparent source of sulfate in unsaturated-zone pore water at the Sheffield site is the oxidation of sulfide minerals.

Although average concentrations of SO4~2(aq) were higher off-site than on-site, the shapes of curves that depict sulfate concentrations with respect to depth (fig. 26) are similar for both locations (with the exception of an anom alously high SO4 value in the Peoria Loess). As previously mentioned, the high sulfate concentrations in the Peoria Loess at borehole 585 might not be representative of sulfate concentrations throughout the geologic deposit; there is no obvious source for sulfate in the silt material. An anomalous source for sulfate at borehole 585 could account for the difference in on-site and off-site concentrations.

Highest sulfate concentrations were at depths of 3 m or less both off-site and on-site. Maximum near-surface sulfate concentrations were 720 mg/L in the Peoria Loess at borehole 585, 390 mg/L in on-site fill material, and 240 mg/L in the clayey-silt trench caps. The fill material and clayey-silt cap on-site had the highest percentage of off-site material mixed with them. The off-site material used on-site was obtained from coal-mining overburden from the area. The decrease in sulfate concentrations below 3 m is possibly due to sulfate precipitation.

Sulfate concentrations in the Radnor Till, the Hulick Till Member of the Glasford Formation, and the Toulon Member ranged from 30 to 280 mg/L and had a mean of 130 mg/L. These sulfate concentrations were similar to those found in ground water that ranged from 13 to 710 mg/L and averaged 140 mg/L.

Other Inorganic Constituents

Chloride concentrations can be indicative of the leaching of waste materials from burial sites (Johnson and Cartwright, 1980; Freeze and Cherry, 1979, p. 436). Concentrations of chloride in lysimeter pore-water samples ranged from 0.1 to 73 mg/L and had a mean of 18 mg/L. Mean chloride concentrations were higher on-site (23 mg/L) than off-site (8.4 mg/L). Highest chloride concentrations in the unsaturated zone were from the clayey-silt trench caps and from below the trenches, in the Toulon Member and near the Toulon Member/Hulick Till Member interface. As previously mentioned, the high chloride concentration of 43 mg/L at borehole 585E does not appear to represent natural conditions elsewhere in the Peoria Loess. Highest chloride concentrations in the saturated zone were from wells located on-site.

The average silica concentration from lysimeter pore- water samples was 53 mg/L. Concentrations of silica in ground water averaged 12 mg/L. Silica concentrations in ground water collected from sandstones and shales are ordinarily between 2 and 60 mg/L (Hem, 1985, p. 69-73).

Lowest silica concentrations in pore water were from on-site, above-trench sediments; mean concentrations


ON-SITE OFF-SITE

PEORIA LOESS

ENCH MATERIAL

H I I I I h

10

H I I h H I I-H \

HULICK TILL MEMBER GLASFORD FORMATIO I I I I | ( CALCIUM

MAGNESIUM

SODIUM

0 10

NASILT

RO

TOULON MEMBER I I I I i I I I

0 510

CONCENTRATION, IN MILLIEQUIVALENTS PER LITER

CONCENTRATION, IN MILLIEQUIVALENTS PER LITER

Figure 23. Average concentrations of calcium, magnesium, and sodium in pore water from lithologic units on-site (above-trench and below-trench lysimeters) and off-site (borehole 585 lysimeters) from July 1982 through May 1984.


SODIUM, IN MILLIEQUIVALENTS PER LITER10

505

10010

505

100

10

505

100

10

| SODIUM

MONTMORILLONITE

0,0 50 100 MONTMORILLONITE, PERCENTAGE OF CLAY-MINERAL FRACTION

Figure 24. Average concentration of sodium in pore water relative to average percentage of montmorillonite in the clay-mineral fraction of four lithologic units off-site (bore hole 585 lysimeters) from October 1982 through May 1984.

ranged from 20 mg/L in the Peoria Loess to 40 mg/L in the clayey-silt cap. Mean concentrations in geologic materials below the trenches and off-site ranged from 53 mg/L in the Hulick Till Member to 82 mg/L in the Peoria Loess. Likely sources of silica in the pore-water samples include (1) the desorption of monomeric silica from the soil matrix (Wood and Signer, 1975, p. 486-488), (2) the leaching of silica and cations from alumino silicates by water high in carbon dioxide, (3) the dissolution of montmorillonite, and (4) the dissolution of oxidized plant material (Reesman and others, 1975). The lower concentrations in the on-site, above- trench sediments possibly result from trench-construction activities; reworking the sediments may have accelerated the leaching process and depleted much of the silica-source materials.

The highest silica concentration, 120 mg/L, occurred in the Toulon Member below trench 2. Silica concentrations greater than 100 mg/L may indicate saturation with respect to silicate minerals present (Thorstenson and others, 1979, p. 1488; Reesman and others, 1975, p. 12-2); WATEQF results indicated supersaturation.

MOLAR RATIO OF CALCIUM TO MAGNESIUM IN SOLUTION, IN LOGARITHM (BASE 10) UNITS

0 0.02 0.04 0.06 0.06 0.10 0.12 0.14 0.16 0.16 0.20

ROXANA SILT

/ RADNOR t / TILL

MEMBER

(GLASFORD FORMATION).

TOULON - MEMBER


CALCIUM IN SOIL, IN MILLIEQUIVALENTS PER 100 GRAMS

Figure 25. Calcium content of geologic materials and molar ratios of calcium to magnesium in pore water relative to depth and geologic material off-site (borehole 585 lysimeters).

Comparisons between on-site, above-trench and below-trench pore-water silica concentrations show a sea sonal trend (fig. 27). The high silica concentrations in late summer and early fall in samples from above-trench lysim eters indicate an increase of about 25 to 35 mg/L of silica in above-trench unsaturated-zone water. This increase could be due partly to the lysimeters proximity to decaying plant material. Lovering (1959) stated that grasses, such as those present at the Sheffield site, accumulate about 3.5 percent of their mass as silica. Silica in plant material is concen trated by plant decay and is transformed into a more soluble form of silica as organic matter. Seasonal shifts in silica concentrations of about 20 mg/L in samples from below- trench lysimeters indicate seasonally due to something other than proximity to decaying plant tissue.

The high concentrations of zinc present in precipita tion (average of 1,300 |xg/L) are not present in typical unsaturated-zone pore waters (340 |xg/L) at the site proba bly because at pH ranges in pore water of 6.8-9.2, zinc is strongly adsorbed by manganese or iron hydroxides (Stumm and Morgan, 1981, p. 625-640; Jenne, 1977). These oxides are ubiquitous in soils that are not strongly reducing. Additionally, organic matter will adsorb zinc, and zinc can substitute for aluminum in montmorillonite clays. Water that had average zinc concentrations greater than 200


ON-SITE OFF-SITE

COocUJ 3I- LLJ

UJ O 6

CO

Q

12

15

FILL

MATERIAL

CLAYEY-SILT CAP _

TRENCH MATERIAL ~

TOULON MEMBER


HULICK TILL MEMBER

(QLASFORD FORMATION)

PEORIA

LOESS

ROXANA SILT

RADNOR TILL MEMBER


TOULON MEMBER


100 200 300 400 500 600 0 100 200 300

SULFATE CONCENTRATION, IN MILLIGRAMS PER LITER

400 500 600

Figure 26. Average concentration of sulfate in pore water from lithologic units on-site (above-trench and below-trench lysimeters) and off-site (borehole 585 lysimeters) from July 1982 through May 1984.

was either from lysimeters constructed, in part, with galva nized materials or from lysimeters located below the trenches, and hence, the contribution of the decaying metal waste containers was a factor. Zinc concentrations in pore-water lysimeters from off-site, where no galvanized materials were used in construction, averaged 30 (xg/L.

The oxidation of pyrite probably is the source of most of the iron in the pore water. Most of the iron released during this oxidation process likely sorbs to soil particles or precipitates as an oxide or hydroxide (B.F. Jones, oral commun., 1984) and, thus, shows no correlation to high sulfate concentrations. However, mass-balance calculations indicate that if the iron present in the sediments and the pore water was derived from pyrite oxidation, this reaction would have been sufficient to produce the sulfate concen trations that exist in the pore water.

Lysimeters yielding water samples with the highest iron concentrations also had high concentrations of zinc; however, not all lysimeters yielding water with high zinc concentrations had correspondingly high iron concentra tions. High iron concentrations did not appear to be related to lysimeter construction materials nor to trench proximity. All the water from wells in the saturated zone had high iron concentrations due to steel well casings.

Dissolved Organic Carbon

DOC that occurs naturally in the unsaturated zone is contributed by the breakdown of plant and animal matter that was recently deposited on or near the land surface and from oil shales and coal of the Carbondale Formation. DOC also may originate from solvents, petroleum products, plastics, scintillation fluids, plant and animal tissues, and other organic wastes buried with the radioactive wastes.

DOC concentrations were highest in water samples from below-trench lysimeters (average of 32 mg/L) (tables 10 and 11). The highest average DOC concentrations in water samples from the below-trench lysimeters were from lysimeters located in the Toulon Member (50 mg/L) and near the Toulon Member/Hulick Till Member interface (39 mg/L). Average concentrations of DOC in water near the interface were higher in July 1983 (45 mg/L) than in March 1983 (28 mg/L). Primary annual water movement below the trenches in 1983 occurred in mid-May (Mills and Healy, 1987). Concentrations of DOC in water samples probably were elevated in May by the flushing of DOC from the trenches due to rain-water and snowmelt percolation and remained elevated after the water had moved through.

Average DOC concentrations in water from on-site, above-trench lysimeters, excluding lysimeter 88, were


80

Ot60

LdCO 02 40

Z 20

1 I I I I I I I I I I I I I I 1 ABOVE-TRENCH

............. BELOW-TRENCH

m SAMPLE DATE

i T

ASOND.JFMAMJ J ASOND.J FMAM 1982 1983 1984

Figure 27. Average concentration of silica in pore water from above-trench and below-trench lysi meters from August 1982 through May 1984.

about three times as high (8.5 mg/L) as in water from off-site lysimeters (2.9 mg/L) and saturated-zone water (2.3 mg/L). Lysimeter 88, which was installed just below the compacted clayey-silt cap into the trench-fill material, yielded water having a DOC concentration (63 mg/L) as high as concentrations below the trenches. Concentrations of DOC in water samples had a positive correlation with tritium in water samples.

Tritium

Natural concentrations of tritium in pore water at the Sheffield site are near the analytical detection limit. Pore water that has greater concentrations of tritium originates, at least partly, from the waste material. Waste-derived sources of tritium include tritiated water in containers, tritium that has exchanged with pore water from solids, and biologic decomposition of tritiated organic wastes.

Tritium migration appears to be directly related to water movement in the unsaturated zone. Tritium move ment in the gaseous phase has not been detected at the Sheffield site (Striegl and Ruhl, 1986, p. 725). Tritium concentrations in the unsaturated zone often change in response to the seasonal movement of water. Differential rates of water movement through the various lithologic units and along interfaces between lithologic units, and the variability in the source terms cause variable rates of tritium migration and, hence, areal variability of tritium concentra

tions. This variability can be observed in concentrations of tritium in soil cores (table 19) taken at the time of tunnel construction, where slower migration rates through the till apparently resulted in lower tritium concentrations in the till than in the sand at the same altitude or distance from the trenches. The variability of tritium concentrations around the Toulon Member/Hulick Till Member interface is evi dence of the importance of these interfaces as flow routes through the unsaturated zone.

Seasonal movement of water through the unsaturated zone initiates the migration of pore water stored in contact with the waste and also leaches radionuclides from the waste as water moves through the trenches. High tritium concentrations in water samples from below-trench lysim eters in spring months (fig. 19) reflect the annual wetting cycle (Mills and Healy, 1987, p. 178). High tritium concentrations in samples from some lysimeters above the trenches occur during the summer and early fall when evapotranspiration rates are high (fig. 17). This seasonal increase in tritium is caused by rewetting of the surface sediments as tritiated pore water moves upward from the trenches. The upward movement of tritiated water during high evapotranspiration periods also was indicated by trit ium in the tissue of plant-cover material at the site (M.P. deVries, oral commun., 1985). In addition to seasonal water movement, molecular diffusion (Freeze and Cherry, 1979, p. 103) may dictate tritium-concentration changes.


300

oti

LdtO

OID 00

200

100

PORE WATER. ABOVE TRENCH

PORE WATER, BELOW TRENCH

GROUND WATER, ON-SITE

GROUND WATER, OFF-SITE

SAMPLE DATE

i i i i i i i i

JASONDJFMAMJJASONDJFMAM 1982 | 1983 | 1984

Figure 28. Average concentration of tritium in pore water and ground water from July 1982 through May 1984.

The amount of tritium available for migration changes as the waste containers deteriorate and as the water available to cause migration increases with trench-cap deterioration. Collapse holes that develop in trench caps may allow water to move through a trench in amounts greater than usual and at atypical times. This movement is exemplified by the previously discussed incident in which tritium concentrations at three below-trench locations increased dramatically following the development of sev eral collapse holes during a large precipitation event (see "Disturbed Unsaturated Zone, Below Trench"). These col lapse holes may have allowed the movement of significant quantities of water through previously isolated wastes. Water movement was not detected in connection with this precipitation event at other tunnel-area locations. Mills and Healy (1987, p. 183) also discuss an incident in which an estimated 1,700 liters of water entered one trench at the Sheffield site during a single precipitation event.

Both instantaneous and continuous releases of tritium from the waste containers may occur. An instantaneous release of tritium, such as may occur when waste containers break down, may move through the unsaturated zone as a slug over several months and over a number of precipitation events. Instantaneous releases of tritium, as measured at below-trench lysimeters, show a gradual increase in tritium concentrations followed by a gradual decline. A continuous tritium release may result in continuously increasing tritium

concentrations until a steady state is reached; the concen trations stabilize until the tritium source is exhausted and a gradual decline begins. These long-term fluctuations in tritium concentrations have been observed in water samples from several below-trench lysimeters. The early variability of tritium concentrations in the soil cores along the length of the tunnel has become less variable (as observed in pore- water samples).

In general, tritium concentrations increased during the 2-year study period. Tritium concentrations, however, decreased in water from some lysimeters while increasing at others. Figure 28 shows trends in tritium concentrations in pore water and ground water in the vicinity of the Sheffield site during July 1982 through May 1984; the values repre sent average concentrations on dates when samples were obtained from all instruments located at the specified sample sites (all above-trench lysimeters, for example). Most notable increases in tritium concentrations were in pore water below the trenches and in ground water on-site. The greatest tritium concentrations in ground water were in water samples from on-site wells. However, because of the complex nature of ground-water flow at the site (Foster and others, 1984), it is not always possible to relate tritium concentrations in the saturated zone to the proximity of the sampling point to the trenches. The movement of tritiated water may be short-circuited in the unsaturated zone, as lateral flow occurs along boundaries between geologic units


OFF-SITE PRECIPITATIONJL

ON-SITE

FILL MATERIAL 1 i£i3_

PEORIA LOESS 1,2,5

C 585D

ROXANA SILT4,5,6

585C

TOULON MEMBER

3.6 /

( W524

^- <

~""v

W502 }7'

Ry

585B

HULICK TILL MEMBER I

2,3,4

585A )

RADNOR TILL MEMBER

2,4,6 -

TOULONMEMBER

5,6

<P284 966g) C82_83_6J[) ( W528 W523

HULICK TILL MEMBER 2,3,4

EXPLANATION

STRATIGRAPHIC MEMBERS BELONG TO GLASFORD FORMATION SCHEMATIC LITHOLOGIC BOUNDARY

> FLOW PATHDESIGNATED INSTRUMENTS IN FLOW PATHS

GEOCHEMICAL PROCESS

1-CARBON DIOXIDE PRODUCTION 4-CATION EXCHANGE

5-DISSOLUTION OF

38 87

2-CARBONATE DISSOLUTION

3-PYRITE OXIDATION

FELDSPARS

6-CALCITE AND SULFATE PRECIPITATION

Figure 29. Generalized flow paths of water in the unsaturated and saturated zones, and reactions occurring in each

lithologic unit.

of contrasting permeability. This phenomenon has been described at the Sheffield site by Mills and Healy (1987, p. 183) and might account for the unexpectedly rapid migra tion of tritium along a flow path in the southeast corner of the site (Foster and others, 1984, p. 23).

Contributing Influences

Changes in water chemistry in the unsaturated zone resulted in part from dissolution reactions involving calcite, dolomite, and montmorillonite; the oxidation of pyrite; cation-exchange reactions; sorption of zinc by iron- and manganese-oxides and hydroxides; precipitation of calcite and sulfate; and the transport of DOC and tritium from the trenches. Information gained from other unsaturated-zone flow studies at the Sheffield site (Foster and others, 1984;

Mills and Healy, 1987) was used to construct water-flow paths that show the lysimeters that are hydraulically down- gradient from one another. Flow paths and geochemical reactions that are thought to occur in each lithologic unit are shown in figure 29.

Average differences in chemistry of water between lysimeters located on-site and off-site are depicted in figure 30 and tables 10 and 11. The major differences between on-site and off-site water chemistry were the elevated tritium and DOC concentrations and the slight decrease in sodium concentrations in on-site water; these differences are attributed to the effects of waste burial and removal of Roxana Silt and Radnor Till Member from on-site.

Below-trench pore-water chemistry varied depending on proximity to the Toulon Member/Hulick Till Member interface. Lysimeters near the interface had more seasonally varied water chemistry than those not near the interface;


CO

NC

EN

TR

AT

ION

, IN

LO

GA

RIT

HM

(B

AS

E

10)

UN

ITS

PE

OR

IA L

OE

SS

HU

LIC

K T

ILL

ME

MB

ER

TO

ULO

N M

EM

BE

R

TRE

NC

H M

ATE

RIA

L (G

LAS

FOR

D F

OR

MA

TIO

N)

(GLA

SFO

RD

FO

RM

ATI

ON

)ro

o

ro

to

.^,

0

10

*-

10

o

is)

*-

ro

FILL

MA

TER

IAL

AN

D

CLA

YE

Y-S

ILT

CA

P10

J*

. 10

3 3-

sr1

B>

-

"

3

J+M

O

p

»'

uL

W

! Is

i' ? 3

« =f

3

$

fD

W

| |1

(/I

^

^

O

^

CDS

S5

Q

-

rt

^^

Hi

O

O

t

3

en

a ff

"5

^~3

O

- Q

--D

s 35"

-^

3-

fD

v^

Q

en

to

^5*

Jo

Ul

S

00 T

3u

i o

O

I^ 3

en n rn fD

-i i if

^" o

3 era

fD

n*-^

r-

S|

K3

S.

r+

^

o ?

C

enera

-^

3-

fD

ro CO * U!

1

T

^ CJ

Hg

£jji

_

, Df

e%

^

1

II "ilt»

i'£>

.

t-

-TJg 1-

1-

i

fe rj_. E

g:

D«L

,

'

IB HT&

O"t*

-

t-

-TT

rj-

flk f

cr

,

1

n-W

- '

«£ *>.

£H=" "f

lk

1.

o z 1 0)

H m

CO

NC

EN

TR

AT

ION

, IN

LO

GA

RIT

HM

(B

AS

E

10)

UN

ITS

"LL

-fc '

TOU

LON

ME

MB

ER

R

AD

NO

R T

ILL

ME

MB

ER

R

OX

AN

AS

ILT

P

EO

RIA

LO

ES

S

1 '

11

\_ \

°

to *

2:

C

"*

3

3 1 T 1

>-

^

£

(GLA

SFO

RD

FO

RM

ATI

ON

)»

1

1 I

i^-

|sj

ols3

^-ioo

|^>

'^'

|s>

o|sji|i'^>

o|s>

>-

|i-

w 3

fc

o*'

_

^1

*

«*

>..

^7

v

^

lE

"11

1

*1

*= i

r

«t3

52

ff«E

a ro

S"

mr

§0>

H

00

C

33

?»

- ^

=5

>C

>

C

31

? s

! ? 8

i 3

a*£ ?

fl f

i5 3

^

3

~*

SS

5"

lr

ow

£

03 fj

5

§0§.

2$

w

r^ o

2

ui

c* ®

S

-^o *

S 5

_k

8 3

"S 5

i if!!

01$*

*il

0~0

=^ ®

00

'-j

fe- o

n "Jo

It

Ik °

1fe

'

I lo

0,

CJ

D- t

D- Is)

fc.

1

Bg k |J^

|« t

b-

1

t=Is rn UIw

1-

O n n 00 H m

33

-1

?0

^W

a

o I X*

J"

these differences may be explained by mixing of various chemistries of pore waters by lateral flow at the interface (M.P. deVries, oral commun., 1985). The major effect of the trenches was to contribute DOC and tritium to the pore water.

Off-site, the Roxana Silt contributed substantial quantities of sodium to solution from montmorillonite dissolution and associated cation-exchange reactions. The Radnor Till Member provided exchange surfaces for mag nesium.

SUMMARY

The geologic materials found in undisturbed and disturbed unsaturated deposits were described and the change in chemistry of infiltrating water was defined at a low-level radioactive-waste disposal site near Sheffield, Illinois. The ability to sample water effectively from the unsaturated zone using ceramic-cup soil-water pressure- vacuum lysimeters was evaluated.

Precipitation was collected in a stainless-steel collec tor six times during a 6-month period (June through December 1983). Pore water was collected monthly from 30 soil-water pressure-vacuum lysimeters during a 2-year period (1982-84). On-site lysimeters were installed above, within, and below trenches. Lysimeters that were located below trenches were installed through the wall of a 90-m- long by 2-m-diameter tunnel that extends beneath trenches 11, 3, 2, and 1. Five lysimeters were located 30 m east of the tunnel in undisturbed materials outside the site bound ary. The saturated zone was sampled for 5 years (1978-83) as part of another study. Chemical data of water from seven wells near the lysimeters were compared to chemical data of water from the lysimeters.

The ionic composition of precipitation at the site was calcium zinc sulfate, and it had an average pH of 4.6. The average concentration of zinc in precipitation was 1,300 M-g/L. The ionic composition of precipitation infiltrating the unsaturated zone changed to calcium sulfate off-site and to calcium bicarbonate on-site within 0.3 m of the land surface and had an average pH of 7.9; below that depth, pH averaged 7.5, and the ionic composition generally was calcium magnesium bicarbonate.

Some variability in water type of pore water was noted. Pore water from one lysimeter installed in the Hulick Till Member of the Glasford Formation on-site was calcium magnesium sulfate, and pore water from one lysimeter in the Roxana Silt off-site was sodium bicarbonate sulfate. Alkalinity concentrations (as CaCO3) of pore water ranged from 87 to 820 mg/L. The pH values ranged from 6.8 to 9.2 and were highest in water samples from the Toulon Member of the Glasford Formation. DOC concentrations were higher than the background level in water from a few on-site lysimeters close to the trenches. Tritium was the only

radionuclide found in the pore water. The highest concen tration of tritium was 1,380 nCi/L in a pore-water sample collected from trench material. Median concentrations of tritium in pore water at above-trench and below-trench lysimeter locations were 11 and 18 nCi/L, respectively. Tritium concentrations in the below-trench, tunnel-area geologic deposits ranged from 0.2 to 450 nCi/L. Water chemistry was most variable near the sloping Toulon Member/Hulick Till Member interface, a major pathway for unsaturated-zone flow.

The ionic composition of water from the saturated zone was magnesium bicarbonate except in well 502, where it was sodium magnesium bicarbonate. The pH values of ground water ranged from 6.2 to 9.0, and alkalinities ranged from 36 to 1,150 mg/L. Average silica concentra tions were lower in the saturated zone (12 mg/L) than in the unsaturated zone (53 mg/L). DOC concentrations were near the background level in all wells. Tritium was the only radionuclide detected in the saturated zone, and the highest concentration (170 nCi/L) was from a well on-site.

The highest specific conductances in the unsaturated zone occurred where the highest alkalinity and DOC con centrations occurred. The cations and anions that were dominant in the pore water also were dominant in the geologic materials.

Geochemical modeling indicated that nearly all unsaturated-zone pore water and saturated-zone waters were supersaturated with respect to calcite and dolomite. Con centrations of calcium, magnesium, and bicarbonate in unsaturated-zone pore water were increased by the dissolu tion of carbonates. Cation-exchange reactions caused con centrations of calcium and magnesium to decrease and concentrations of sodium to increase. The oxidation of pyrite was the likely source of sulfate at the site. On-site sulfate concentrations could be correlated with the amount of clayey-silt materials present. Trench-construction activ ities appear to account for low silica concentrations in pore water from on-site, near-surface sediments.

The major differences between on-site and off-site water chemistry were the higher tritium and DOC concen trations and reduced sodium concentrations on-site; these differences are attributed to the effects of waste burial and removal of the Roxana Silt and the Radnor Till Member of the Glasford Formation from on-site.

Tritium and DOC concentrations were highest near the trenches. Tritium and DOC concentrations in ground water were near background levels in off-site areas. Tritium concentrations in ground water varied seasonally in on-site areas. Seasonally elevated tritium concentrations in water samples from the below-trench lysimeters resulted from increased percolation of pore water during the spring; elevated concentrations in the above-trench lysimeter sam ples occurred during the summer as a result of increased evapotranspiration. Large increases in tritium concentra tions in pore water from three below-trench lysimeters

Summary 37

apparently coincided with increased rainfall and the devel opment of collapse holes in the trench surface above the tunnel. Both instantaneous and continuous releases in trit ium from the trenches may occur, each represented by different patterns of increasing and decreasing pore-water tritium concentrations.

Off-site, the Roxana Silt contributed substantial quantities of sodium to solution from montmorillonite dissolution and associated cation-exchange reactions. The Radnor Till Member provided exchange surfaces for mag nesium.

Ceramic-cup soil-water pressure-vacuum lysimeters were determined to be an adequate means of collecting representative samples from the unsaturated zone. The constituents whose concentrations may have changed because of lysimeter-cup leaching and degassing were silica (concentrations increased), certain heavy metals (concen trations either increased or decreased depending on the metal), and pH. All other major cations and anions appeared to be unaffected by the use of ceramic-cup pore-water pressure-vacuum lysimeters.

SELECTED REFERENCES

American Public Health Association, 1985, Standard methods for the examination of water and wastewater (16th ed.): Wash ington, D.C., American Public Health Association, 1,268 p.

Barnes, Ivan, 1964, Field measurement of alkalinity and pH: U.S. Geological Survey Water-Supply Paper 1535-H, 17 p.

Blake, G.R., 1965, Bulk density, in Black, C.A., ed., Methods of soil analysis: Madison, Wis., American Society of Agron omy, p. 374-390.

Bohn, H.L., McNeal, B.L., and O'Connor, G.A., 1979, Soil chemistry: New York, Wiley, 329 p.

Brackensiek, D.L., Osborn, H.B., and Rawls, W.J., coordina tors, 1979, Field manual for research in agricultural hydrol ogy: U.S. Department of Agriculture, Agricultural Handbook 224, 550 p.

Brady, N.C., 1974, The nature and properties of soils: New York, MacMillan, 639 p.

Broadbent, F.E., 1973, Organics, in Proceedings of the Joint Conference on Recycling Municipal Sludges and Effluents on Land, Champaign, 111., July 9-13, 1973: National Associa tion of State Universities and Land-Grant Colleges, p. 97-101.

Brown, Eugene, Skougstad, M.W., and Fishman, M.J., 1970, Methods for collection and analysis of water samples for dissolved minerals and gases: U.S. Geological Survey Tech niques of Water-Resources Investigations, book 5, chap. Al, 160 p.

Brunaer, S.E., Emmett, P.H., and Teller, E., 1938, Adsorption of gases in multimolecular layers: Journal of the American Chemical Society, v. 60, p. 309-319.

Buhler, Shirrell, Firester, L., Buhler, R., Heiberger, R.M., and Laurance, D., 1983, P-STAT users manual: Princeton, N.J., P-STAT, Inc., 719 p.

Butler, J.N., 1982, Carbon dioxide equilibria and their applica tions: Reading, Mass., Addison-Wesley, 259 p.

Chapelle, F.H., and Knobel, L.L., 1983, Aqueous geochemistry and the exchangeable cation composition of glauconite in the Aquia aquifer, Maryland: Groundwater, v. 21, no. 3, p. 343-352.

Chapman, H.D., 1965, Cation exchange capacity, in Black, C.A., ed., Methods of soil analysis: Madison, Wis., American Society of Agronomy, p. 896-898.

Claassen, H.C., 1982, Guidelines and techniques for obtaining water samples that accurately represent the water chemistry of the aquifer: U.S. Geological Survey Open-File Report 82-1024, 49 p.

Crouthamel, C.E., 1970, Applied gamma-ray spectrometry, revised by F. Adams and R. Dams (2d ed.): Oxford, Pergamon Press, 747 p.

Day, P.R., 1965, Particle size analysis, in Black, C.A., ed., Methods in soil analysis: Madison, Wis., American Society of Agronomy, p. 545-566.

Dreimanis, Aleksis, 1962, Quantitative gasometric determination of calcite and dolomite by using chittick apparatus: Journal of Sedimentary Petrology, v. 32, no. 3, p. 520-529.

Drever, J.F., 1982, The geochemistry of natural waters: Engle- wood Cliffs, N.J., Prentice-Hall, 388 p.

Foster, J.B., and Erickson, J.R., 1980, Preliminary report on the hydrogeology of a low-level radioactive-waste disposal site near Sheffield, Illinois: U.S. Geological Survey Open-File Report 79-1545, 87 p.

Foster, J.B., Erickson, J.R., and Healy, R.W., 1984, Hydroge ology of a low-level radioactive-waste disposal site near Sheffield, Illinois: U.S. Geological Survey Water-Resources Investigations Report 83-4125, 83 p.

Foster, J.B., Garklavs, George, and Mackey, G.W., 1984a, Geologic and hydrologic data collected during 1976 to 1984 at the Sheffield low-level radioactive-waste disposal site and adjacent areas, Sheffield, Illinois: U.S. Geological Survey Open-File Report 83-926, 261 p.

1984b, Hydrogeologic setting east of a low-level radioactive-waste disposal site near Sheffield,'Illinois: U.S. Geological Survey Water-Resources Investigations Report 84-4183, 20 p.

Freeze, A.R., and Cherry, J.A., 1979, Groundwater: Englewood Cliffs, N.J., Prentice-Hall, 604 p.

Garklavs, George, and Healy, R.W., 1986, Hydrogeology, ground-water flow, and tritium movement at a low-level radioactive-waste disposal site near Sheffield, Illinois: U.S. Geological Survey Water-Resources Investigations Report 86-4153, 35 p.

Gray, J.R., and McGovern, L.L., 1986, Collapse and erosion at the low-level radioactive-waste burial site near Sheffield, Illinois, in Proceedings of the Seventh Annual Participants Information Meeting DOE Low-Level Waste Management Program: Department of Energy, CONF-8509121, p. 737-753.

Hansen, E.A., and Harris, A.R., 1975, Validity of soil water samples collected with porous ceramic cups: Soil Science Society of America Proceedings, v. 39, p. 528-536.

Healy, R.W., 1989, Seepage through a hazardous-waste trench cover: Journal of Hydrology, v. 108, no. 1-4, p. 213-234.


Healy, R.W., deVries, M.P., and Striegl, R.G., 1986, Concepts and data-collection techniques used in a study of the unsaturated zone at a low-level radioactive-waste disposal site near Sheffield, Illinois: U.S. Geological Survey Water-Resources Investigations Report 85-4228, 37 p.

Healy, R.W., deVries, M.P., and Sturrock, A.M., Jr., 1989, Evapotranspiration and microclimate at a low-level radioactive-waste disposal site in northwestern Illinois: U.S. Geological Survey Water-Supply Paper 2327, 44 p.

Hem, J.D., 1972, Geochemical controls of groundwater quality, in Proceedings of the Fourteenth Water-Quality Conference, Groundwater Quality and Treatment, Champaign, 111.: Uni versity of Illinois Bulletin, v. 69, no. 120, p. 7-18.

1985, Study and interpretation of the chemical character istics of natural water (3d ed.): U.S. Geological Survey Water-Supply Paper 2254, 263 p.

Henderson, Thomas, 1984, Geochemistry of ground-water in two sandstone aquifer systems in the Northern Great Plains in parts of Montana, Wyoming, North Dakota, and South Dakota: U.S. Geological Survey Professional Paper 1402-C, 84 p.

Hendry, M.J., Cherry, J.A., Wallick, E.I., 1986, Origin and distribution of sulfate in a fractured till in southern Alberta, Canada: Water Resources Research, v. 22, no. 1, p. 45-61.

Horr, C.A., 1959, A survey of analytical methods for the determination of strontium in natural water: U.S. Geological Survey Water-Supply Paper 1496-A, p. 1-18.

Hosteller, P.B., 1964, The degree of saturation of magnesium and calcium carbonate minerals in natural waters: International Association of Science Hydrology Commission of Subterra nean Waters Publication 64, p. 34-49.

Hurlbut, C.S., and Klein, Cornelis, 1977, Manual of mineralogy: New York, Wiley, 532 p.

Illinois Environmental Protection Agency, 1982, Manual of lab methods: Springfield, 111., Division of Labs, 1,028 p.

Jenne, E.A., 1977, Trace element sorption by sediments and soils sites and processes, in Chappel, W., and Petersen, K., eds., Symposium on molybdenum in the environment, v. 2: New York, Marcel Dekker, p. 425-553.

Johnson, T.M., and Cartwright, Keros, 1980, Monitoring of leachate migration in the unsaturated zone in the vicinity of sanitary landfills: Illinois State Geological Survey Circular 514, 82 p.

Levin, M., and Verhagen, B.Th., 1985, Soil moisture studies in the unsaturated zone at the South African nuclear waste repository facility, in Hydrology of rocks of low permeabil ity: International Association of Hydrogeologists, Memoires, v. 17, pt. l,p. 236-247.

Levering, T.S., 1959, Significance of accumulator plants in rock weathering: Geological Society of America Bulletin, v. 70, p. 781-800.

Martland, M.M., and Kemper, W.D., 1965, Surface area, in Black, C.A., ed., Methods of soil analysis: Madison, Wis., American Society of Agronomy, p. 532-544.

Means, J.L., Crerar, D.A., Borcsik, M.P., and Duguid, J.O., 1978, Adsorption of Co and selected actinides by Mn and Fe oxides in soils and sediments: Geochimica et Cosmochimica Acta, v. 42, p. 1763-1773.

Mills, P.C., and Healy, R.W. ,1987, Water and tritium movement through variably saturated glacial deposits at a low-level

radioactive-waste disposal site near Sheffield, Illinois, in Proceedings of the FOCUS Conference on Midwestern Ground Water Issues, Indianapolis, Ind.: National Water Well Association, p. 169-186.

1991, Water and tritium movement through the unsaturatedzone at a low-level radioactive-waste disposal site near Sheffield, Illinois, 1981-85: U.S. Geological Survey Open- File Report 89-271, 109 p.

Moran, S.R., Groenewold, G.H., and Cherry, J.A., 1978, Geo logic, hydrologic, and geochemical concepts and techniques in overburden characterization for mined-land reclamation: North Dakota Geological Survey Report of Investigations No. 63, 152 p.

Nuclear Measurements Corporation, 1975, Instruction manual, proportional counting system NMC Model PC-5, 22 p.

Parkhurst, D.L., Plummer, L.N., and Thorstenson, D.C., 1982, BALANCE a computer program for calculating mass trans fer for geochemical reactions in ground water: U.S. Geolog ical Survey Water-Resources Investigations 82-14, 33 p.

Peters, C.A., and Healy, R.W., 1988, Representativeness of pore-water samples collected from the unsaturated zone using pressure-vacuum lysimeters: Ground Water Monitoring Review, v. 8, p. 96-101.

Piciulo, Paul, Shea, C.E., and Barletta, R.E., 1982, Analysis of soil from an area adjacent to a low-level radioactive-waste disposal site, at Sheffield, Illinois: Brookhaven National Laboratory, BNL-NUREG-31667, 43 p.

Pietrzak, R.F., and Dayal, R., 1982, Evaluation of isotope migration land burial water chemistry at a commercially operated low-level radioactive-waste disposal site: Brookhaven National Laboratory, BNL-NUREG-31567, 34 p.

Piper, A.M., 1944, A graphical procedure in the geochemical interpretation of water analyses: American Geophysical Union Transcripts, v. 25, p. 914-923.

Piskin, Kemal, and Bergstrom, R.E., 1975, Glacial drift in Illinois thickness and character: Illinois State Geological Survey Circular 490, 35 p.

Plummer, L.N., Jones, B.F., and Truesdale, A.H., 1976, WATE- QF a Fortran IV version of WATEQ, a computer program for calculating chemical equilibria of natural waters: U.S. Geological Survey Water-Resources Investigations 76-13, 61 p.

Plummer, L.N., Wigley, T.M.L., and Parkhurst, D.L., 1978, The kinetics of calcite dissolution in CO2-water systems at 5 to 60°C and 0.0 to 1.0 atm CO2 : American Journal of Science, v. 278, no. 2, p. 179-216.

Reardon, E.J., Mozeto, A.A., and Fritz, P., 1980, Recharge in northern clime calcareous sandy soils Soil water chemical and carbon-14 evolution: Geochimica et Cosmochimica Acta, v. 44, p. 1723-1735.

Reesman, A.L., Walton, A.W., Sprinkle, C.L., Godfrey, A.E., and Smith, D.B., 1975, Hydro-geochemistry in a carbonate basin-geomorphic and environmental implications: Water Resources Research Center, University of Tennessee, Resources Report No. 44, 261 p.

SAS Institute, Inc., 1982, SAS user's guide Statistics, 1982 edition: Gary, N.C., 921 p.

Selected References 39

Shepard, P.P., 1954, Nomenclature based on sand-silt-clay ratios: Journal of Sedimentary Petrology, v. 24, no. 3, p. 151-158.

Skougstad, M.W., Fishman, M.J., Friedman, L.C., Erdmann, D.E., and Duncan, Sandra, eds., 1979, Methods for deter mination of inorganic substances in water and fluvial sedi ments: U.S. Geological Survey Techniques of Water- Resources Investigations, book 5, chap. Al, 626 p.

Skougstad, M.W., and Horr, C.A., 1963, Occurrence and distri bution of strontium in natural water: U.S. Geological Survey Water-Supply Paper 1496-D, p. 55-97.

State of Illinois, Department of Registration and Education, 1958, Atlas of Illinois resources, Section 1 Water resources and climate: Division of Industrial Planning and Development, 58 p.

Striegl, R.G., 1988, Distribution of gases in the unsaturated zone at a low-level radioactive-waste disposal site near Sheffield, Illinois: U.S. Geological Survey Water-Resources Investiga tions Report 88-4025, 69 p.

Striegl, R.G., and Ruhl, P.M., 1986, Variability in the partial pressures of gases in the unsaturated zone adjacent to a low-level radioactive-waste disposal site near Sheffield, Illi nois, in Proceedings of Seventh Annual Participants Informa tion Meeting DOE Low-Level Waste Management Program: Department of Energy, CONF-8509121, p. 725-736.

Stumm, Werner, and Morgan, J.J., 1981, Aquatic chemistry (2d ed.): New York, Wiley Interscience, 780 p.

Suarez, D.L., 1982, Graphical calculation of ion concentration in calcium carbonate and/or gypsum soil solutions: Journal of Environmental Quality, v. 11, no. 2, p. 302-308.

1986, A soil water extractor that minimizes CO2 degassing and pH errors: Water Resources Research, v. 22, no. 6, p. 876-880.

Thatcher, L.L., Janzer, V.J., and Edwards, K.K., 1977, Methods for determination of radioactive substances in water and fluvial sediments: U.S. Geological Survey Techniques of Water-Resources Investigations, book 5, chap. A5, 95 p.

Thornburn, T.H., 1963, Surface deposits of Illinois a guide for soil engineers: Urbana, 111., University of Illinois Engineer ing Experiment Station Circular No. 80, 135 p.

Thorstenson, D.C., Fisher, D.W., and Croft, M.G., 1979, The geochemistry of the Fox Hills-Basal Hell Creek Aquifer in southwestern North Dakota and northwestern South Dakota: Water Resources Research, v. 15, no. 6, p. 1479-1498.

Thorstenson, D.C., Weeks, E.P., Haas, H., and Fisher, D.W., 1983, Distribution of gaseous CO2 in the subsoil unsaturated zone of the western U.S. Great Plains: Radiocarbon, v. 25, no. 2, p. 315-346.

Tsai, T.C., Morrison, R.D., and Stearns, R.J., 1980, Validity of the porous cup vacuum/suction lysimeter as a sampling tool for vadose zone waters: Huntington Beach, Calif., Calscience Research, Inc., lip.

Turkenian, K.K., and Kulp, J.L., 1956, Geochemistry of stron tium: Geochimica et Cosmochimica Acta, v. 10, p. 245-296.

U.S. Department of Commerce, National Oceanic and Atmo spheric Administration, 1939-79, Climatological data for Illinois, annual summary: Asheville, N.C., Environmental Data Information Service, National Climatic Center.

U.S. Environmental Protection Agency, 1976, Quality criteria for water, 256 p.

U.S. Nuclear Regulatory Commission, 1975, 10CFR, 20, B, II.van Lier, J.A., de Bruyn, P.L., and Overbeek, J.Th.G., 1960,

The solubility of quartz: Journal of Physical Chemistry, v. 64, p. 1675-1682.

Verhagen, B.Th., Smith, P.E., McGeorge, I., and Dziembowski, Z., 1979, Tritium profiles in Kalahari sands as a measure of rain-water recharge, in Proceedings of an International Sym posium on Isotope Hydrology, June 19-23, 1978, Neuher- berg, Germany: Vienna, Austria, International Atomic Energy Agency, v. 2, p. 733.

Vomocil, J.A., 1965, Porosity, in Black, C.A., ed., Methods of soil analysis: Madison, Wis., American Society of Agron omy, p. 299-314.

Wallace, Debbie, 1980, Water quality provinces of Illinois: Illinois Water Information System Report of Investigation No. 27, 82 p.

Warrick, A.W., and Amoozegar-Fard, A., 1977, Soil-water regimes near porous cup water samplers: Water Resources Research, v. 13, no. 1, p. 203-207.

Willman, H.B., and Frye, J.C., 1970, Pleistocene stratigraphy of Illinois: Illinois State Geological Survey Bulletin 94, 204 p.

Wolfe, R.G., 1967, Weathering of Woodstock Granite near Baltimore, Maryland: American Journal of Science, v. 265, p. 106-117.

Wood, W.W., and Signor, D.C., 1975, Geochemical factors affecting artificial recharge in the unsaturated zone: Water Resources Research, v. 9, no. 2, p. 486-488.


TABLES

Table 1. Laboratory procedures for analyses of physical and chemical properties of geologic materials

Property Analytical method Reference Agency1

Particle size................... Pipette........................... Day, 1965 ......Bulk density .................. Core ............................ Blake, 1965.....Carbonate mineralogy.......... Chittick analysis.................. Dreimanis, 1962

Clay mineralogy............... X-ray diffraction ................. Hurlbut and Klein, 1977 .Total mineralogy .............. Petrographic analysis ............. Hurlbut and Klein, 1977 .pH ........................... 1:1 distilled water to soil mixture.. Pietrzak and Dayal, 1982Organic matter ................ Ignition.......................... Broadbent, 1973 ........Soluble ions .................. X-rayfluorescence, neutron Pietrzak and Dayal, 1982

activation, atomic absorption,gravimetric.

Gamma spectral............... Gamma-ray spectrometry.......... Crouthamel, 1970 .......Cation-exchange capacity ...... Ammonium displacement ......... Chapman, 1965 .........Porosity ...................... Calculated (BD/SPD2), Freeze and Cherry, 1979,

Mercury porsimeter. Vomocil, 1965.Surface area .................. Nitrogen adsorption by monosorb Brunaer, Emmett, and

analyzer. Teller, 1938.

1 ISGS Illinois State Geological Survey; UI Geo. University of Illinois Geology Department; USGS U.S. Geological Survey laboratory at Denver, Colorado; USGS IL Dist. U.S. Geological Survey laboratory at Urbana, Illinois; BNL Brookhaven National Laboratory; TJW Geo. University of Wisconsin Geology Department; UI ERL University of Illinois Environmental Resources Laboratory; and USGS NRP U.S. Geological Survey laboratory at Reston, Virginia.

2 BD/SPD Bulk density/standard particle density of 2.65 grams per cubic centimeter.

ISGS, USGS, UI Geo. USGS IL Dist BNL, UW Geo., UI

Geo. ISGS UI Geo. BNL BNL BNL

USGS EL Dist., UI ERL USGS, BNL, UI Geo. USGS IL Dist. USGS USGS NRP

Table 2. Concentrations of selected constituents for a known water sample, for the known sample collected through a leached porous-ceramic cup, and the percent age of difference between the concentrations[mg/L, milligrams per liter; (xg/L, micrograms per liter]

Constituent

Calcium ......Magnesium . . . Sodium .......Sulfate .......Chloride ......Cadmium .....Copper .......Iron ..........Manganese. . . . Strontium .....Zinc ..........

Concentration of known

sample

33 mg/L15 mg/L 57 mg/L54 mg/L67 mg/L36fJig/L58 jJig/L

330 jJig/L73 [LgfL 53 jJig/L4.7 it p/T

Concentration of sample collected

through leached ceramic cup

34 rnp/T18 mg/L 58 mg/L59 mg/L72 mg/L7fig/L

40 fJig/L1 Q 1 1 a/T

16 JJLg/L

80 |j-g/L88 |xg/L

Percentage difference

+3+20+2+9+7

-81-31-94-78 +51

+ 110

Table 3. Mean concentrations of selected metals in water samples collected using lysimeters that contain, and that do not contain, galvanized materials [All mean values are in micrograms per liter]

Metals

Galvanized materials

Numberof

samplesMean

No galvanized materials

Numberof Percentage

Mean samples difference

Iron..........Lead .........Manganese....Zinc..........

11011

140690

32333532

962554

460

35283433

+ 14.6-56.0

+ 159.3+50.0

Tables 43

Table 4. Values of specific conductance, pH, alkalinity (as CaCO3), and chloride for untreated and for silica-saturated solutions from well 505, distilled water, and distilled water acidified to pH 2.7 with sulfuric acid[Specific conductance in microsiemens per centimeter at 25 degrees Celsius; pH in standard units; alkalinity and chloride in milligrams per liter; <, less than]

Well 505

Solutions

Untreated ......

Saturated with silica flour. . .

Specific conductance

1,260

1,140

PH

7.4

7.9

Alkalinity

420

420

Distilled water

Specific Chloride conductance

<17 0

3 12

PH

6.1

6.1

Alkalinity Chloride

4 <10

4 3

Distilled water acidified to pH 2.7


620

570

PH

2.7

2.7

Alkalinity

0

0

Chloride

<9

3

Table 5. Concentrations of selected constituents in pore water collected at -20 and -80 kilopascals (kPa) suction [mg/L, milligrams per liter; |xg/L, micrograms per liter]

Constituents (unit of concentration)

Calcium (mg/L) ...................Magnesium (mg/L) ................Sodium (mg/L) ....................Alkalinity (mg/L as CaCO3). .......Silica (mg/L). .....................

Copper (u,g/L) ....................Manganese (u,g/L) .................Strontium (u,g/L) ..................Zinc (jo-g/L) .......................

-20 kPa1

..... 110

..... 53

..... 50

..... 410

..... 43

..... 20

..... 11

..... 440

..... 160

-80 kPa2

1105449

41036

208

380110

1 Sampled December 7, 1983; vacuum lysimeter 62 (Hulick Till Member of the Glasford Formation).

2 Sampled December 8, 1983; vacuum lysimeter 62 (Hulick Till Member of the Glasford Formation).

Table 6. Concentrations of selected constituents uncomposited and composited pore-water samples [mg/L, milligrams per liter; |xg/L, micrograms per liter]

for

Constituents (unit of concentration or value)

pH (standard units). .............Calcium (mg/L). ................Magnesium (mg/L). .............Sodium (mg/L) .................Alkalinity (mg/L as CaCO3)

Sulfate (mg/L) ..................Chloride (mg/L) ................

Copper (M-g/L) ..................Iron (M-g/L) .....................

Manganese (u,g/L) ..............Zinc (M-g/L) ....................

Uncomposited

7.71307114

540

6814342010

38110

Composited

7.51307213

540

6714404030

39130

Table 7. Mean values of physical properties for geologic materials[|o,m, micrometers; m2/g, square meters per gram; g/cm3 , grams per cubic centimeter; <, less than; >, greater than; dashes indicate no data]

Particle-size distribution1 (percentage of total sample)

Geologic unit

Fill material. ................

Clayey-silt cap ..............Trench material . ...

Peoria Loess ................Roxana Silt .................

Clay <4jxm

........... 24

........... 15

........... 17

Silt 4-62 jxm

68

81

81

Sand >62 |xm

8

4

2

Surface area (m2/g)

38.5

53.8

Bulk density (g/cm3 )

2 1.65

1.77

1.61

1.45

1.50

Bulk porosity (percent)

38

33

39

45

43

Number of samples

12

31

28

138

14

Radnor Till Member of the Glasford Formation ......................

Toulon Member of the Glasford29 53 18 47.8 '1.90

1 Includes data from Foster and others (1984b).2 Sixty-four samples.3 Two samples.

28 47

Formation ...........................Hulick Till Member of the Glasford

6

30

10

43

84

27

31.1

50.1

1.60

1.85

40

30

34

60


Table 8. Mean values of chemical properties for geologic materials [meq/100 g, milliequivalents per 100 grams; >, greater than]

Iron1 OrganicCation- (percentage matter1

Number pH1 Number exchange Number Calcium1 Number Magnesium1 Number of fine Number (percentageof (standard of capacity2 of (meq/100 g of (meq/100 g of sands, of of total,

Geologic unit samples units) samples (meq/100 g) samples as Ca) samples as Mg) samples by weight) samples by weight)

Roxana Silt .......

Rador Till Member of the Glasford

Toulon Member of the Glasford

Hulick Till Member of the Glasford

3

2

4

4

1

7.7

7.4

7.5

8.0

7.1

123

12

42

60

39

14.0

17.4

20.2

4.4

16.5

130

17

51

66

43

>190

17

50

59

>105

130

17

51

66

43

>73

3.6

22

19

>35

4

3

5

4

3

3.2

3.3

8.3

.4

1.4

4

3

5

4

3

2.1

.1

.5

.3

1.9

1 Data from Piciulo and others (1982).2 Data from Piciulo and others (1982); Foster and others (1984b).

Table 9. Mean values of mineralogic properties for geologic materials[Dashes indicate no data]

Carbonate minerals2 (percentage of silt and

Petrographic analysis1 clay-size particles, (percentage of fine sands) by weight)

Geologic unit

Fill material

Roxana Silt ........

Rador Till Memberof the GlasfordFormation. .......

Toulon Memberof the Glasford

Hulick Till Memberof the Glasford

Numberof

samples Matrix Quartz Feldspar Marble

0 - - - -

4 31 41 5 0

0 - - - -

4 32 33 6 0

9 4 49 6 20

0 - - - -

NumberOrganic Calcite ofmatter Volcanic cement Other samples

- - - - 24

5 2 11 5 88

- - - - 17

8 8 - 13 44

0 8 5 8 38

- - - - 24

Total

16.0

21.7

4.0

10.6

6.0

16.0

Calcite/dolomite

ratio

0.01

.14

.11

.12

.13

.26

Clay minerals1 (percentage of clay-size

particles, by weight)

Numberof

samples

15

124

10

39

33

34

Mont-moril-lonite

69

58

82

44

17

30

Illite

17

77

10

4?

6?

43

Kaoliniteand

chlorite

14

15

8

14

21

27

1 Data from Foster and others (1984b).2 Data from Piciulo and others (1982); Foster and others (1984b).

Tables 45

Table 10. Mean, standard deviation, and number of pore-water samples analyzed for selected constituents at off-site(borehole 585) lysimeters[mg/L, milligrams per liter; nCi/L, nanocuries per liter; std. dev., standard deviation; dashes indicate no data]

Calcium Site number (mg/L

(geologic unit sampled) as Ca)

585A (Toulon Member1 ): Mean ................Std. dev. .............Number ..............

585B (Toulon Member): Mean ................Std. dev. .............Number ..............

585C (Radnor Till Member1 ): Mean ................Std. dev. .............Number ..............

585D (Roxana Silt): Mean ................Std. dev. .............Number ..............

585E (Peoria Loess): Mean ................Std. dev. .............Number ..............

130 304

140 30 6

110 20

3

100 20

3

120

1

Magnesium (mg/L

as Mg)

7623

4

68 9 6

47 15

3

494 3

47

1

Sodium (mg/L as Na)

8422

3

31 45

4522

3

200 50

3

49

1

Alkalinity (mg/L

as CaCO3 )

470 40 20

580 100 21

560 50 10

480 30 17

330 30 10

Sulfate (mg/L

as SO4)

200 60

5

170 30

7

110 40

3

330 200

4

510 300

2

Chloride (mg/L as Cl)

10 9 5

4.0 3.0 8

5.7 2.93

9.0 5.0 4

25 25

2

Silica (mg/L

as SiO2)

74 4 4

63 9 8

73 8 3

76 93

82 20

2

Tritium (nCi/L)

1.0.4

25

1.4 1.2

25

.2

.1 20

.4

.3 24

.3

.2 9

Dissolved organic carbon (mg/L)

2.2

1

3.7

1

2.2

1

3.5

1

1 Of the Glasford Formation.


Table 11. Mean, standard deviation, and number of pore-water samples for selected constituents at on-site lysimeters [mg/L, milligrams per liter; nCi/L, nanocuries per liter; std. dev., standard deviation; dashes indicate no data]

Site number (geologic unit sampled)

38 (Clayey-silt cap):

Std. dev. .............Number ..............

39 (Fill material):

Std. dev. .............Number ..............

40 (Peoria Loess)::

Std. dev. .............Number ..............

51 (Peoria Loess): Mean ................Std. dev. .............Number ..............

52 (Fill material):

Std. dev. .............Number ..............

87 (Clayey-silt cap): Mean ................Std. dev. ............. Number ..............

88 (Trench material): Mean ................Std. dev. .............Number ..............

89 (Peoria Loess): Mean ................Std. dev. .............Number ..............

90 (Fill material): Mean ................Std. dev. .............Number ..............

91 (Trench material): Mean ................Std. dev. .............Number ..............



Calcium (mg/L as Ca)

16020

4

16072

12072

8028

2

72

1

190

1

14072

130

1

190

1

_

Magnesium (mg/L

as Mg)

81154

6222

5092

2282

55

1

93

1

6222

48

1

98

1

_

Sodiurr (mg/L as Na)

1834

2022

3.3.1

2

1.9.6

2

15

1

20

1

1212

17

1

15

1

_

i Alkalinity (mg/L

as CaCO3)

Above trench

4306016

440110

9

4702215

36039

9

460190

4

43052

6

490107

370159

350354

740178

390

1

560544

Sulfate (mg/L

as SO4)

230160

5

390

1

2173

1552

280

1

8212

42142

120

1

_

Chloride (mg/L as Cl)

45105

2842

8.28.13

4.15.83

72

1

2012

9.14.12

27

1

_

Silica (mg/L

as SiO2)

3314

5

1822

2624

3

5.83 52

36

1

74

1

45182

28

1

58

1

_

Tritium (nCi/L)

118

43

2.32.2

27

5 23.3

41

3.11.8

25

.5

.524

7235 34

1,2706033

584028

6.54.0

25

421133

165

22

9.12.8

24

Dissolved organic carbon

(mg/L)

1151

14

1

5.032

2.9

1

10

1

63

1

_

Tables 47

Table 11. Mean, standard deviation, and number of pore-water samples for selected constituents at on-site lysimeters Continued[mg/L, milligrams per liter; nCi/L, nanocuries per liter; std. dev., standard deviation; dashes indicate no data]

Site number (geologic unit sampled)


Magnesium (mg/L

as Mg)

Sodium (mg/L as Na)

Alkalinity (mg/L

as CaCO3)

Sulfate (mg/L

as SO4)

Chloride (mg/L asCI)

Silica (mg/L

as SiO2)

Dissolved Tritium organic carbon (nCi/L) (mg/L)

Below trench

26 (Toulon Member1 ): Mean ................Std. dev. .............Number ..............

61 (Hulick Till Member1 ): Mean ................Std. dev. .............Number ..............

62 (Hulick Till Member):

Std. dev. .............Number ..............


Std. dev. .............

64 (Toulon Member): Mean ................Std. dev. .............Number ..............

65 (Toulon Member): Mean ................Std. dev. .............Number ..............

66 (Tulon Member): Mean ................Std. dev. .............Number ..............


Std. dev. .............

81 (Hulick Till Member): Mean ................Std. dev. .............Number ..............


Std. dev. .............Number ..............

83 (Hulick Till Member): Mean ................Std. dev. .............



29

1

110 63

110 5 6

120 63

35

1

120 15 3

12072

1304 5

130

1

10072

32 10 4

46

1

762 3

53 1 6

632 3

290

1

62 93

61 12

72 1 5

90

1

48 42

15 5 4

67

1

16 13

67 38

6

20 63

88

1

21 7 3

12 12

155 5

28

1

16 42

14 3 5

510 12 11

410 21 15

420 36 13

520 210

4

390 110

6

29052 12

450 38 11

530 36 13

510 46 11

370 35 14

160 64 10

56 42

13037

5

12021

2

120

1

260 02

1101 2

67 3 5

130

1

44

1

38 9 4

4.8 1.62

27 7 5

20 32

73

1

32 52

6.9 .1

2

14 .4

5

19

1

7.0

1

24 31 4

34

1

56 8 3

41 3 6

5914 3

120

1

48 5 3

54 62

51 155

50

1

67 62

59 20

5

39 1921

4.4 4.3

31

250 18035

6.62.2

33

10022 27

200 110 26

30 17 11

25 7

32

1.8 3.4

30

160 80 31

33 1032

1.92.2

32

3.7 .9

21

55

1

54 182

18 62

54

1

41

1

5.8

1

6.3

1

8.8

1

12

1

13

1

70

1

Of the Glasford Formation.


Table 12. Equilibrium constants used in calculation of saturation indices

Mineral specie

Aragonite ..............Calcite.................Dolomite. ..............Gypsum ...............Magnesite ..............Montmorillonite ........Pyrite..................

Equilibrium constant,

temperature adjusted

........ -2.5890

........ -2.2970

........ -9.4360

........ -.0280

........ -6.1690

........ 60.355

........ 11.3000

Equilibrium constant at 25 degrees

Celsius

-8.3360-8.4800

-17.0900-4.6020-8.2400

-45.2600-18.4800

Table 13. Saturation indices for calcite and dolomite on-site and off-site [Dashes indicate not applicable]

Geologic unit

Fill material. .....Clayey-silt cap ......................Trench material .....................Peoria Loess ........................Hulick Till Member1 ................Hulick Till Member (near Toulon

Member1 /Hulick Till Member interface) .........................

Peoria Loess ........................Roxana Silt .........................Rador Till Member1 .................Toulon Member (shallow) ...........Toulon Member (deep) ..............

Mean

0.79.65.40.69.54

.53

.591.04

.47

.45

.51

Calcite

Number

On-site3535

12

14Off-site

13333

Standard deviation

0.57.43.17.61.27

.41

.83

.05

.01

.56

Mean

0.891.33

.771.221.10

1.20

.961.98

.72

.811.23

Dolomite

Number

3535

12

14

13333

Standard deviation

1.021.44

.811.331.09

1.11

1.90.53.59

1.44

Of the Glasford Formation.

Tables 49

Table 14. Physical characteristics of water-chemistry sampling sites [m, meters]

Site number (see fig. 6) Type of sampling site LocationHeight above (+) or below (-)

land surface (m) Sample material

0001

585A585B585C585D585E

3839405152

8788899091

9293

2661626364

6566688182

838496

502505507523524

527528

Precipitation

Lysimeterdo.do.do.do.

do.do.do.do.do.

do.do.do.do.do.

do.do.

do.do.do.do.do.

do.do.do.do.do.

do.do.do.

Welldo.do.do.do.

do.do.

Off-site

Off-sitedo.do.do.do.

On-site, above trenchdo.do.do.do.

do.do.do.do.do.

do.do.

On-site, below trenchdo.do.do.do.

do.do.do.do.do.

do.do.do.

Off-siteOn-site

do.do.

Off-site

do.On-site

+2.5

-13.1-10.1-6.7-3.5-1.2

-1.4-.6

-1.0-.5_ o

-1.1-2.3-1.3-.7

-2.2

-1.0-.4

-11.6-7.0

-11.6-11.6-11.6

-11.6-11.6-11.6-9.1-8.2

-7.6-10.4-11.6

-11.9-8.2-8.4-8.3-8.4

-6.9-8.4

Atmospheric deposition

Toulon Member1 .Toulon Member.Radnor Till Member1 .Roxana Silt.Peoria Loess.

Clayey-silt cap.Fill material.Peoria Loess.Peoria Loess.Fill material.

Clayey-silt cap.Trench material.Peoria Loess.Fill material.Trench material.

Fill material.Fill material.

Toulon Member.Hulick Till Member1 .Hulick Till Member.Hulick Till Member.Toulon Member.

Toulon Member.Toulon Member.Hulick Till Member.Hulick Till Member.Hulick Till Member.

Hulick Till Member.Hulick Till Member.Hulick Till Member.

Hulick Till Member.Hulick Till Member.Hulick Till Member.Hulick Till Member.Toulon Member.

Toulon Member.Hulick Till Member.


Table 15. Chemical analyses of precipitation[jiS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; n-g/L, micrograms per liter; nCi/L, nanocuries per liter; <, less than; dashes indicate no data]

Specific Date of conductance sample (|jiS/cm)

pH (standard

units)

Calcium(mg/L asCa)

Magnesium (mg/L

asMg)

Sodium (mg/L asNa)

Alkalinity (mg/L

as CaCO3 )

Sulfate(mg/L

as SO4)

Chloride Silica Iron (mg/L (mg/L (M-g/L as Cl) as SiO2) as Fe)

Zinc (M-g/L

as Zn)

Dissolved organic

Tritium carbon (nCi/L) (mg/L)

Site 000106-30-8308-24-8308-26-8311-23-8312-02-8312-06-83

257040

<10<10

20

6.46.13.87.57.55.5

2.2 1.51.3

0.2

.3

.4

0.7

.2

.2

59

<5<5

3

6.3

7.54.7

0.6 0.1 130_ _ _

<.2 .1 140.7 .1 50

_ _ _

1,400

1,3001,200

0.2 - _.2 -.2 -.2 -.2 -


Table 16. Chemical analyses of pore water in the unsaturated zone from off-site[(iS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; (Ag/L, micrograms per liter; nCi/L, nanocuries per liter; <, less than; dashes indicate no data]

Specific Date of conductance sample ((x,S/cm)

pH Calcium (standard (mg/L

units) as Ca)

Magnesium Sodium Alkalinity Sulfate Chloride (mg/L (mg/L (mg/L (mg/L (mg/L

as Mg) as Na) as CaCO3) as SO4) as Cl)

Silica Iron Zinc (mg/L ((Ag/L ((Ag/L Tritium

as SiO2) as Fe) as Zn) (nCi/L)


Site 585A (Tulon Member of the Glasford Formation)06-10-8206-22-8207-07-8207-21-8208-19-8209-02-8209-16-8209-28-8210-07-8210-22-8211-10-8202-25-8303-24-8304-08-8304-15-8304-22-8305-19-8306-02-8307-07-8308-02-8308-24-8310-13-8311-08-8311-18-8312-08-8301-26-8403-29-8404-24-8405-10-8406-20-84

1,1301,1401,1801,0601,1301,0201,180

1,1801,1201,360

1,4801,3801,3001,3601,1601,2901,2201,0001,0801,1101,0101,2601,0401,0601,0401,0001,0401,120

7.5 -7.2 -7.2 1207.1 -7.2 -7.4 -7.3 -

7.8 -7.7 1807.3 -

7.1 1107.3 -

7.5 -7.6 -7.5 -7.3 110

7.4 -7.2 - 8.4 -7.6 -7.7 -7.7 - _

7.5 -

- - 400 - -_ _ 440 _ _64 - 460 130 25- - 370 - -- - 440 150 9.9- - 480 - -_ _ 460 - -- - 470 - -_ _ _ _ _

110 59 460 230 6.2_ _ 470 - -_ _ _ _ 66 99 410 280 4.9_____ - - 520 - -_____64 95 500 200 4.3 - - 510 - -- - 490 - -_ _ _ _ __ _ _ _ __ _ 470 - -

- - 500 - -- - 520 - -- - 520 - - - - 520 - -

- - - 1.5- - - 1.7- - - .778 - - -- - - 1.5- - - 1.1_ _ _ _- - - 1.376 - - 1.7- - - .9- - - .270 10 - 1.0- - - .9- - - 1.1- - - 1.3- - - .8- - - .272 7 40 .8- - - 1.0- - - .7- - - .7- - - 1.1- - - 1.3- - - 1.7- - - .8- - - 1.0_ _ _ _- - - 1.0_ _ _ _

2.2

Site 585 B (Toulon Member)06-10-8206-22-8207-07-8207-21-8208-19-8208-25-8209-02-8209-16-8209-28-8210-07-8210-22-8211-10-8211-23-8202-25-8303-24-8304-08-8304-15-8305-19-8306-02-8307-07-83

1,5701,5501,7201,6801,6301,0501,3801,400

1,3401,1201,3001,270

1,2201,2201,1401,2001,1701,280

8.0 -7.4 -- 190

7.9 -7.3 -

7.8 -7.5 -_

7.6 -7.6 -7.3 -7.5 -_

7.3 1207.3 -_

7.2 -7.2 -7.2 160

- - 540 - -- - 670 - -77 - 680 - 11- - 730 - -- - 720 180 5.0 - - 760 - -- - 680 - -- - 650 - - - - 630 120 2.2- - 600 - -- - 570 - -_ _ _ _51 36 460 120 2.9 _ _ _ _ _- - 570 - -_____76 35 530 200 2.6

- - - 1.675 - - 1.9_ _ _ _77 - - - - - - 1.2- - - 1.7_ _ _ _- - - 1.864 5-1.7- - - 1.1- - - 1.0- - - .255 4 20 1.1- - - .9- - - .9- - - .9- - - .257 3 20 .7

3.7

Tables 51

Table 16. Chemical analyses of pore water in the unsaturated zone from off-site Continued[|xS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; |xg/L, micrograms per liter; nCi/L, nanocuries per liter; <, less than; dashes indicate no data]

Specific Date of conductance sample (|o,S/cm)

P H (standard

units)

Calcium Magnesium Sodium Alkalinity Sulfate Chloride Silica (mg/L (mg/L (mg/L (mg/L (mg/L (mg/L (mg/L as Ca) as Mg) as Na) as CaCO3) as SO4) as Cl) as SiO2)

Iron Zinc (M-g/L (|o.g/L Tritium as Fe) as Zn) (nCi/L)

Dissolved organic carbon(mg/L)

Site 585B (Tulon Member) Continued08-02-8308-24-8310-13-831 1-08-8311-18-8312-02-8312-08-8303-29-8404-24-8405-10-8405-16-8406-20-84

1,0001,0501,1101,0701,0401,0001,1401,0501,0801,1401,0801,180

7.57.3 8.27.37.7

7.77.4

130 67 29 440 190 3.0 59- - - 430 - - -_ _ _____ _____

130 66 27 440 180 2.5 56- - - 500 - - -- - _ 520 - - - _____

130 69 27 520 170 2.7 59_ _ _ 520 - - -

_ _ 910 50 .7- - .6- - 1.0- - 1.4- - 2.0<3 20 .9- - 1.4 , - - 1.310 70 6.9_ _ _

Site 585C (Radnor Till Member of the Glasford Formation)10-22-8211-10-8211-23-8202-25-8303-24-8304-08-8304-15-8304-22-8305-19-8306-02-8307-07-8308-24-8310-13-8311-08-8312-02-8312-08-8301-25-8402-23-8403-29-8404-24-8405-10-8405-17-8406-20-84

815935850875

1,1101,0801,0401,0301,0601,0201,0501,0601,2001,1401,060

9501,100

8901,0401,0001,020

1,150

7.77.57.87.67.67.4

7.47.67.37.27.67.5

8.27.6

7.87.9

7.7

89 32 70 - 150 8.8 82_ _ ______ _ ______ _ _____

120 47 35 460 120 5.2 65 _ _ ______ _ _____- - - 540 - - - _____

130 62 30 520 73 3.0 72- - _ 600 - - -_ _ _ 640 - - -_ _ _____ _____

««n ^j^j\j - - - 580 - - -_ _ _____- - _ 580 - - -_ _ _ 540 _ _ -_ _ ______ _ _____- - - 590 - - -

5 60 -_ _ 2- - .2_ _ 2

3 20 .3- - .2- - .2_ _ 2- - .2- - .2

9 20 .2- - .2- - .2- - .5_ _ 3_ _ 2- - .2_ _ 2- - .3 _ _ 3- - .3

2.2

Site 585D (Roxana Silt)08-19-8209-02-8209-16-8209-28-8210-07-8210-22-8211-10-8211-23-8202-25-8303-24-8304-08-8304-15-8304-22-8305-19-8306-02-83

1,4401,3401,630

1,7901,7002,0001,780

2,2501,7501,5801,3201,0601,020

7.38.27.6 8.38.17.88.0

7.97.7

7.87.67.6

- - - 480 240 15 86- - _ 520 - - - 530 - - -- - - 520 - - - _____

120 52 250 500 - - -COfi

^J4*\J

- - _ 500 - - -_ _ ______ _ _ 440 610 11 - _ _ _____

Afif) *TUV

__ __ __________

J

- - 1.2_ _ _- - 1.0

5 30 1.1_ _ 3- - .2_ _ j- .2- - .2_ _ 2- - .2_ _ 2- - .2


Table 16. Chemical analyses of pore water in the unsaturated zone from off-site Continued[jxS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; jxg/L, micrograms per liter; nCi/L, nanocuries per liter; <, less than; dashes indicate no data]

Specific Date of conductance sample (n,S/cm)


units) as Ca)



Silica Iron Zinc (mg/L (|Ag/L (|Ag/L Tritium



Site 585D (Roxana Silt) Continued07-07-8308-02-8308-24-8311-08-8311-18-8312-02-8312-08-8301-26-8403-29-8404-24-8405-10-8405-16-8406-20-84

1,4901,3801,4601,4201,340

1,280950

1,2401,220

980

1,080980

1,060

7.6 95 7.6 - _ 7.4 887.8 -7.2 -7.9 -_

7.9 -7.5 -

49 200 470 300 6.5_ _ _ _ _- - 490 - -_ _ _ _ ______

45 160 460 - -- - 500 - -- - 460 - -- - 450 - - - - 450 160 3.5- - 460 - -

71 <3 20 .2- - - .2_ _ _ .2- - - .2_ _ _ 3

- - - .471 20 30 .3- - - .2

_ 7 tin

- - - .3- - - .2_ _ _ _

Site 585E (Peoria Loess)07-06-8208-19-8211-10-8211-23-8202-25-83

03-24-8304-22-8306-02-8307-07-8301-26-84

03-29-8404-24-8405-17-84

1,4201,3401,1301,040

1,170 900870

1,050

1,1501,0201,020

7.8 -7.3 -7.9 -7.8 -

7.7 -7.8 -7.6 -7.7 -7.6 -

7.4 -7.9 -7.9 120

- - 280 - -- - 330 720 43- - 310 - -- - 310 - -_____

- - 370 - -_ _ _ __ _ _ _ __ _ 300 _ -- - 330 - -

- - 360 - -- - 340 - -47 49 340 300 7.7

96 _ _ _- - - .2

9 in

- - - .9- - - .2_ _ _ _- - - .2- - - .2- - - .2_ _ _ 2_ _ _ _67 10 30 .2

3.5 _

Tables 53

Table 17. Chemical analyses of pore water in the unsaturated zone from on-site, above-trench locations[|jiS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; |xg/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Specific Date of conductance sample (nS/cm)


units) as Ca)



Silica Iron Zinc (mg/L (n-g/L (n-g/L Tritium



Site 38 (Clayey-silt cap)07-21-8208-19-8209-02-8209-10-8209-16-8209-22-8209-28-8210-08-8210-14-8210-22-8210-29-8211-04-8211-10-8211-17-8211-23-8212-01-8212-10-8201-13-8302-25-8303-24-8304-08-8304-15-8304-22-8305-12-8305-19-8306-09-8306-23-8307-07-8308-02-8308-24-8309-20-8310-13-8310-27-8311-08-8311-18-8312-02-8303-13-8403-22-8403-29-8405-01-8405-10-8405-17-8405-30-8406-06-8406-20-84

1,160 968966

1,0601,0401,040

1,000

1,050

1,070

1,420

1,490990900950980

1,040

1,1201,240

9501,3801,2701,2601,2201,2001,2001,4701,240

7751,2001,2501,000

1,200

1,250

7.5 -7.5 -8.0 -7.3 -7.6 -7.3 -7.0 - 7.8 160

7.7 -

7.5 - _

7.9 -

7.3 1907.5 - 8.0 -7.6 -7.2 -7.8 -7.5 -7.5 140

7.4 170

7.3 - _

7.2 - 7.4 -

7.7 -

- - 410 - -- - 440 110 51- - 450 - -_ _ _ _ __ _ 450 - -_ _ _ _ _- - 490 - -_ _ _ _ ______95 15 430 95 38 _ _ _ __ _ 440 _ __ _ _ _ _ 440 - -_ _ _ _ _- - 350 - -__________88 21 340 480 58 ______ _ _ _ __ _ _ _ __ _ 390 - - _____60 16 380 210 34_____82 18 450 260 42 _ _ 490 - -_ _ _ _ __ _ _ _ ______ _ _ _ _ _ _ __ _ _ _ _- - 410 - - _ _ _ _ __ _ _ _ __ _ _ _ __ _ _ _- - 590 - -

- - - 1953 - - 21- - - 21_ _ _ 22- - - 20- - - 20- - - 20- - 21- - - 2138 - - 20- - - 19- - - 18_ _ _ Y]- - - 18_ _ _ lg

- - - 16- - - 11_ _ _ 11 1518 8 40 3.5- - - 1.1- 1.1- - - 1.4- - - 1.9_ _ _ 2.1

- - - 2.4_ _ _ 3923 20 60 5.2- - - 7.832 10 30 11- - - 9.5- - - 12- - - 12- - - 12_ _ _ 13 _ _ _ 4^7_ _ _ 14- - - 2.0- - - 1.7- - - 1.1_ _ _ j j_ _ _ 12_ _ _ 11_ _ _ _

_

_

15

7.3

Site 39 (Fill material)07-21-8208-19-8209-02-8209-10-8211-17-8211-23-8212-01-8201-13-83

1,7701,900

1,790

7.9 -8.2 - 8.0 -

- - 500 - -- - 460 - 30_ _ _ _ ___________

- - 270 - -______ _ _ _ _

_ _ _ 2.5- - - 2.5- - - 4.6- - - 11- - - 2.8- - - 2.8

1 f\ 1 »\J

- - - 2.0

_

54 Effects of Low-Level Radioactive-Waste Disposal on Water Chemistry, Ml., 1982-84

Table 17. Chemical analyses of pore water in the unsaturated zone from on-site, above-trench locations Continued[|i,S/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; |JLg/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Specific Date of conductance sample ((iS/cm)


units) as Ca)

Magnesium Sodium Alkalinity Sulfate (mg/L (mg/L (mg/L (mg/L

as Mg) as Na) as CaCO3) as SO4)

Chloride Silica Iron Zinc (mg/L (mg/L (M-g/L (M-g/L Tritium as Cl) as SiO2) as Fe) as Zn) (nCi/L)


Site 39 (Fill materiaO-Continued03-24-8304-08-8304-15-8304-22-8305-05-8305-12-8305-19-8306-09-8306-23-8311-18-8312-02-8302-23-8403-13-8403-22-8403-29-8404-24-8405-01-8405-10-8405-17-8406-06-8406-20-84

1,2701,2001,1201,240

1,4401,4901,5201,580

1,420790

1,380740980

1,4001,0201,0601,400

1,510

7.5 1607.7 -

7.8 -

7.7 -7.3 -7.5 -7.9 -

7.6 -7.5 -

7.5 170

7.6 -

61 19 320 390 _ _ _ _ _ _ _ _ - 410 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _- - 380 -- - 510 -_ _ _ __ _ _ _64 22 510 -_ _ _ _- - 630 -

25 16 9 30 1.7- - - - 1.0- - - - 1.1- - - - 1.3- - - - 1.4_ _ _ _ _- - - - 2.0- - - - 1.7- - - - 2.7- - - - 4.7- - - - 1.8- - - - 1.5- - - - 2.2- - - - .4- - - - 1.0- - - - .5- - - - .8- - - - .8- 19 10 60 5.7- - - - .8_ _ _ _ _

14

Site 40 (Peoria Loess)07-21-8208-19-8209-02-8209-10-8209-16-8209-22-8209-28-8210-08-8210-14-8210-22-8210-29-8211-04-8211-10-8211-17-8211-23-8212-01-8212-10-8201-13-8302-25-8303-24-8304-08-8304-15-8304-22-8305-12-8305-19-8306-23-8307-07-8308-02-8308-24-8309-20-8310-13-8310-27-83

940910793800840848855 870 920 915 870 950650610675750780800870600920770850680

7.6 -7.2 -8.5 -7.3 -7.4 -7.2 -7.7 - _ 8.4 -

7.7 - _

7.8 -

7.5 - 7.2 1307.3 -

7.5 -7.5 -7.3 -7.7 -7.4 120

7.6 -

7.4 -

- - 480 -- - 480 27- - 480 - - - 470 - _ _ 470 - _ _ _ __ _ 440 - - - 470 - - - 480 - - - 480 - 56 3.3 520 23 _ _ _ _ _ _ 440 _ 43 3.2 450 13 - - 460 -_ _ _ _

- - 460 -_ _ _ _

- - - - 5.117 53 - - 4.5- - - - 4.7_ _ _ _ 54- - - - 4.7- - - - 3.8- - - - 5.2- - - - 4.8- - - - 2.7- - - - 3.6- - - - 3.5- - - - 4.9- - - - 2.9- - - - 7.0- - - - 5.0- - - - 2.0- - - - 7.7- - - - 4.4- - - - 5.86.5 18 40 240 9.2- - - - 2.6- - - - 2.9 3.3- - - - 2.9- - - - 4.4- - - - 3.51.0 6.6 390 240 2.1- - - - 5.2- - - - 3.8- - - - 4.0- - - - 4.8- - - - 2.9

2.8 7.3

Tables 55

Table 17. Chemical analyses of pore water in the unsaturated zone from on-site, above-trench locations Continued[jiS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; jig/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Specific Date of conductance sample ((jiS/cm)

pH Calcium Magnesium Sodium Alkalinity Sulfate (standard (mg/L (mg/L (mg/L (mg/L (mg/L

units) as Ca) as Mg) as Na) as CaCO3) as SO4)

Dissolved Chloride Silica Iron Zinc organic

(mg/L (mg/L (ng/L (ng/L Tritium carbon as CD as SiO2) as Fe) as Zn) (nCi/L) (mg/L)

Site 49 (Peoria Loess) Continued11-08-8311-18-8312-02-8303-22-8403-29-8405-01-8405-10-8405-17-8405-30-84

820710825758740

_ _ __ _ __ _ _7.4 - - __ _ __ _ __ _ _

_ _ __ _ _- 430 - _ _ __ _ __ _ _

- - - - 5.9 -- - - - 3.5 -- - - - 8.1 -- - - - 6.7 -- - - - 3.5 -- - - - 22 -- - - - 7.3 -- - - - 7.7 -- - - - 8.9 -

Site 51 (Peoria Loess)11-10-8211-23-8212-01-8202-25-8303-11-8303-24-8304-08-8304-15-8304-22-8305-05-8305-12-8305-19-8306-09-8308-02-8309-20-8310-13-8310-27-8311-08-8311-18-8303-22-8403-29-8404-23-8404-24-8405-01-8405-10-8405-17-8405-30-8406-06-8406-20-84

725700

590520480542

585590490590640725610660715620620 735585610735650 750

7.7 - -7.6 - -_ _ __ _ _

7.4 60 177.4 - -_ _ _

7.8 - -_ _ _

7.8 - -7.8 - -8.1 - -7.6 - -

7.7 - - .. _ _ __ _ __ _ _

7.3 - - _ _7.7 - - _ _ _

7.7 100 287.4 - -_ _ _

7.7 - -

- 360 -- 350 - _ _ 2.3 310 18 _ _ __ _ __ _ _ _ _ _ - 410 11_ _ _

- 410 - _ _ __ _ _

- 300 -_ _ _- 370 - _ _ _

1.4 370 - _ _ _- 390 -

- - - - 1.7 -- - - - 2.6 -- - - - 4.3 -- - - - 3.4 -- - - - 2.7 -1.5 3.4 50 130 2.6 2.9- - - - 1.6 -- - - - 1.3 -- - - - 1.6 -- - - - 1.3 - - - - - 2.0 -- - - - 1.9 -

11 _____- - - - 3.0 -- - - - 3.0 -- - - - 1.8 -- - - - 3.7 -- - - - 2.8 -- - - - 3.5 -- - - - 2.3 -- - - - 5.8 -- - - - 2.1 - - - - - 3.1 -

.1 8.3 10 10 7.8 -- - - - 2.5 -- - - - 8.2 -_ _ _ _ _ _

Site 52 (Fill material)08-27-8209-22-8211-10-8211-23-8212-01-8202-25-8303-24-8304-08-8304-15-8304-22-8305-12-8305-19-8308-02-83

1,260 925750725880885

_ _ _8.3 - -8.2 - -_ _ _ 8.2 72 558.3 - -_ _ _8.4 - -

' 8.7 - -_ _ __ _ _

_ _ __ _ _- 280 -_ _ _

15 320 - _ _ _ _ _ _

- - - - .4 -- - - - 1.5 -- - - - .2 -_ _ _ _ 2 _- - - - .2 -- - - - .2 - 36 60 160 .2 10_ _ _ _ 2 _- - - - .2 -- - - - .2 -- - - - .8 -- - - - .2 -- - - - 1.9 -


Table 17. Chemical analyses of pore water in the unsaturated zone from on-site, above-trench locations Continued[fiS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; fig/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Specific Date of conductance sample (jiS/cm)


units) as Ca)

Dissolved Magnesium Sodium Alkalinity Sulfate Chloride Silica Iron Zinc organic

(mg/L (mg/L (mg/L (mg/L (mg/L (mg/L (jig/L (jig/L Tritium carbon as Mg) as Na) as CaCO3) as SO4) as Cl) as SiO2) as Fe) as Zn) (nCi/L) (mg/L)

Site 52 (Fill materiaD-Continued09-19-8311-08-8311-18-8312-02-8303-29-8404-24-8405-01-8405-10-8405-17-8405-30-8406-06-8406-20-84

1,000720760490660

1,100710910

1,000

1,220

7.8 -7.8 - 7.6 -

7.7 -

_ _ _ _ _ _ _ _ 5 ________ 5_ _ _ _____ .4- - - _____ .5- - - _____!. 5

_ _ 580 _____ .3_ _ _ _____ .2_ _ _ _ _ _ _ _ 4_ _ _ _____ .7- - - _____ .3_ _ _ _____ .4_ _660

_

Site 87 (Clayey-silt cap)04-15-8304-22-8305-12-8305-19-8306-02-8306-09-8306-23-8306-30-8307-07-8307-08-8307-14-8308-02-8308-11-8308-24-8309-19-8309-20-8310-13-8310-27-8311-08-8311-18-8312-02-8302-09-8402-10-8402-23-8403-14-8403-22-8403-29-8404-06-8404-12-8404-18-8404-24-8405-01-8405-10-8405-17-8405-30-8406-06-84

1,4001,5401,4301,5001,3201,4501,4801,5301,4701,4701,5401,2101,4001,4601,3401,3401,3701,3601,3201,2601,1501,1301,440

8201,1401,1401,0601,0701,1301,6401,1201,1501,160

1,220

7.9 -8.4 -7.7 -7.6 -7.8 -7.6 -7.5 -7.4 1907.4 -7.3 - 7.6 -7.8 -

7.8 - 7.3 -8.2 -7.2 -7.8 - 7.4 -

_ _ _ _____99_ _ ______ 91_ _ _ _ _ ___84- 470 ----- 88_ _ ______90_ _ _ _____9i

QS -y^j

- _ _ _____9793 20 460 280 72 74 10 30 99- _ 460 ----- 99 - - _____1QO- - - _____1QO_ _ 370 _____ 110- - - _____HO- - - _____no_ _440____-HO- - - _____HO_ __ _ _____no ______

- - - _____1QO_ _ _ _____59- _______ 66_ _ ______ 94_ _ ______ 52_ _ _ _____39- - 350 _____ 25- - - _____36_ _ _ _____28_ _ _ _____18_ _ _ _____16_ _ ______ 23_ _ ______ 28_ _ _ _____44_ _ _ _____9.4_ _ _ _____24

_ _ _

Tables 57

Table 17. Chemical analyses of pore water in the unsaturated zone from on-site, above-trench locations Continued[(xS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; (xg/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Date of sample


(|xS/cm)

PH (standard

units)


Magnesium (mg/L

as Mg)

Sodium (mg/L as Na)

Alkalinity (mg/L

as CaCO3)

Sulfate (mg/L

as SO4)

Chloride Silica (mg/L (mg/L as Cl) as SiO2)

Iron Zinc (jtg/L (jtg/L as Fe) as Zn)

Tritium (nCi/L)

Dissolvedorganic carbon (mg/L)

Site 88 (Trench material)04-15-8304-22-8305-05-8305-12-8306-02-8306-09-8306-23-8306-30-8307-07-8307-14-8308-02-8308-11-8308-24-8309-19-8309-20-8310-13-8310-27-8311-08-8311-18-8312-02-8302-09-8402-10-8402-23-8403-14-8403-22-8403-29-8404-06-8404-12-8404-18-8404-24-8405-01-8405-10-8405-17-8405-30-8406-06-8406-20-84

9401,080

1,060970

1,1201,0601,1001,0601,170915

1,0201,0401,0101,0001,0201,020965

1,000960

1,0201,040 990960990

1,0001,0101,1201,1001,0201,0001,1001,080

1,020

7.6 - -_ _ _8.4 - -7.6 - -7.8 - -7.6 - -7.5 - -6.9 140 637.3 - - 6.9 - -7.0 - -_ _ _

6.9 - -_ _ __ _ __ _ _ _ _ __ _ _7.3 - -

6.9 - -7.5 - -7.2 - -7.6 - -7.2 - - _ _ _7.2 130 607.2 - -_ _ _7.0 - -

- - _____ i,no_ _ ______- - _____ 1,190- - _____ 1,160- - _____ 1,240- - _____ 1,190- - _____ 1,210- - _____ 1,21013 500 81 21 58 - 860 1,240 ______- - _____ 1,260- - - - - - - 1,180- 490 - - - - - 1,250- - _____ 1,280- - - - _ _ _ 1,260

- 480 - - - - - 1,320- - _____ 1,290- - _____ 1,350- - - - - - - 1,330- - - - - - - 1,320------- 1,180- - _____ 1,230- - _____ 1,310- - _____ 1,350- - - - - - - 1,350- 480 - - - - - 1,280- - _____ 1,300- - - - - - - 1,380- - _____ 1,310- 500 - - - - - 1,270- - - - - - - 1,220- - _____ 1,29011 500 83 19 32 7 20 1,290- - _____ 1,380- - _____ 1,330- 500 - - - - - -

63 _

Site 89 (Peoria Loess)04-15-8304-22-8305-12-8305-19-8306-02-8306-09-8306-23-8306-30-8307-07-8307-08-8307-14-8308-02-8308-11-8308-24-8309-19-83

660735

1,4301,5001,3201,4501,4801,530775775795630720730700

7.9 -7.5 -7.2 -7.4 -7.6 -7.3 -7.6 -6.9 -6.9 -7.1 - 7.3 -7.3 -

_ _ _ _ _ _- - 380 -_ _ _ _ _ _ _ __ _ _ _- - 380 32- - 380 - _ _ _ _- - 360 -_ _ _ _

_ _ _ _ 40- - - - 47- - - - 43- - - - 43 - - - - 47- - - - 516.2 - - - 58- - - - 58 - - - - 93- - - - 92- - - - 110- - - - 130

_


Table 17. Chemical analyses of pore water in the unsaturated zone from on-site, above-trench locations Continued[|xS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; |xg/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Specific Date of conductance sample (|iS/cm)


units) as Ca)

Dissolved Magnesium Sodium Alkalinity Sulfate Chloride Silica Iron Zinc organic

(mg/L (mg/L (mg/L (mg/L (mg/L (mg/L (l^g/L (n-g/L Tritium carbon as Mg) as Na) as CaCO3 ) as SO4) as Cl) as SiO2) as Fe) as Zn) (nCi/L) (mg/L)

Site 89 (Peoria Loess) Continued09-20-8310-13-8310-27-8311-08-8311-18-8312-02-8303-22-8403-29-8404-06-8404-12-8404-18-8404-24-8405-01-8405-10-8405-17-8405-30-8406-06-8406-20-84

705770775755810890950950

1,0801,0801,1501,1201,0101,0601,120

800_925

7.6 -_ _ _ _

7.0 -7.5 -7.2 -7.4 -7.8 -

7.8 1307.4 -_

7.1 -

- - - _____150- -340 _____ 100- - - _____HO_ _ _ _____120- - - _____83 _ _____22_ _ _ _____16- - 380 ----- 20_ _ _ _____26_ _ _ _____27_ _ ______ 24_ _ _ _ _ _ _ _ 14_ _ _ _______ _ _ _____2448 17 360 52 12 28 40 150 32_ _ _ _ _ _ _ _ 17 30- _ 380 ------

Site 90 (Fill material)04-15-8306-02-8306-09-8306-23-8306-30-8307-07-8307-08-8307-14-8308-02-8308-11-8308-24-8309-19-8309-20-8310-13-8310-27-8311-08-8311-18-8312-02-8303-22-8403-29-8404-12-8404-18-8404-24-8405-01-8405-10-8405-17-8405-30-8406-06-84

660550630600588650650905560625640660700830815810890745

/

7.8 -8.6 -8.1 -8.3 -7.6 -7.6 -7.2 -

7.6 -7.8 -

7.7 -

8.1 -_ _

_ _ _ _____4.i_ _ _ _____4.7- - - _____3.6- - - _____5.2- _______ 5.4

- _ 310 ------- _ 390 ----- 6.1_ _ _ __ _____ _ _ _ _ _ _ _ 70- - 380 _____ 5.7

- _ 330 ----- 5.9_ _ _ _____ 6.5- - - _____6.9- - 360 ----- 2.8- - - _____3.g

- - - _____6.8- - - _____6.9

S 8*J * \J

_ _ _ _ _ _ _ _ 44- - _ _____4.2_ _ ______ 10_ _ _ _____io_ _ _ _ _ _ _ _ 71_ _ _ _ _ _ _ _ 23_ _ _ _ _ _ _ _ 92

- - _ _____!. 2_ _ _ _ _____ _ _ _____7.i

Site 91 (Trench material)04-15-8304-22-8305-12-8305-19-8306-02-83

1,4601,5201,4501,400

860

7.0 -7.4 -7.4 -7.9 -

_ _______ 61_ _ _ _____60_ _ _ _ _ _ _ _ 48- -760 _____ 51_ _ _ ______

Tables 59

Table 17. Chemical analyses of pore water in the unsaturated zone from on-site, above-trench locations Continued[(j,S/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; M-g/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Specific Date of conductancesample (n-S/cm)


units) as Ca)

Magnesium Sodium Alkalinity Sulfate Chloride Silica Iron Zinc (mg/L (mg/L (mg/L (mg/L (mg/L (mg/L (fJ-g/L (fJ-g/L Tritium

as Mg) as Na) as CaCO3) as SO4) as Cl) as SiO2) as Fe) as Zn) (nCi/L)


Site 91 (Trench material) Continued06-09-8306-23-8306-30-8307-07-8307-08-83

07-14-8308-02-8308-11-8308-24-8309-19-83

09-20-8310-13-8310-27-8311-08-8311-18-83

12-02-8302-09-8402-10-8402-23-8403-14-84

03-22-8403-29-8404-06-8404-12-8404-18-84

04-24-8405-01-8405-10-8405-17-8405-30-84

06-06-8406-20-84

1,5201,4901,5501,5901,590

1,6201,2401,4301,4401,400

1,4501,4601,2001,3701,370

1,360950

1,4201,1601,100

1,0401,4201,4001,4401,020

1,4001,4501,390

1,450

1,370

7.1 -7.0 -6.9 -6.8 -6.8 -

6.8 -

6.8 -7.2 190

7.1 -

7.1 -7.6 -7.3 -7.3 -

7.2 -

7.1 - 7.0 -

_ _ _ _____51_ _ _ _ _ _ _ _ 52_ _ _ _____54_ _ 750 ______- - 750 ----- 52 - - - _____5Q_ _ ______ 4898 15 730 120 27 58 10 20 49_ _ ______ 48

- - ______ 50- - 720 ----- 47_ _ ______ 42_ _ _ _____5i_ _ ______ 48

- - - _____5Q- - ______ 28_ _ ______ 34

'JQ _7O

_ _______ 39

- - ______ 38- -760 ----- 35_ _ _ _____37- _______ 36- - - _____28

- - 750 ----- 29- - - _____28_ _ _ _____25- - - _____28- - ______ 26

- - ______ 22- _720 ------

Site 92 (Fill material)04-15-8306-02-8307-08-8308-02-8308-11-83

08-24-8309-20-8310-13-8310-27-8311-08-83

11-18-8312-02-8303-29-8404-06-8404-12-84

04-15-8404-18-8404-24-8405-01-8405-10-84

1,150775

930955

1,750 950

7.7 - _ _

8.2 -

7.8 -8.1 -

7.4 -

_ _ _ _____i3_ _ _ _____i6_ _ _ _____25- - - _____20_ _ _ _____21

_ _ _ _____27_ _ _ _____i6- - ______ 20- - ______ 22_ _ ______ 21

- - ______ 20_ _ ______ 13_ _ 390 ----- 9.0_ _ _ _ _ _ _ _ 10_ _ ______ 14

- _______ 9.5_ _ _ _____n_ _ ______ 12_ _ _ _______ _ _ _____i6


Table 17. Chemical analyses of pore water in the unsaturated zone from on-site, above-trench locations Continued[p,S/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; p,g/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Specific Date of conductance sample (jjuS/cm)


units) as Ca)

DissolvedMagnesium Sodium Alkalinity Sulfate Chloride Silica Iron Zinc organic

(mg/L (mg/L (mg/L (mg/L (mg/L (mg/L (n.g/L (n.g/L Tritium carbon as Mg) as Na) as CaCO3 ) as SO4) as CD as SiO2) as Fe) as Zn) (nCi/L) (mg/L)

Site 92 (Fill material) Continued05-17-8405-30-8406-06-84

_ _ _ _____15 __ _ _ _____n __ _ _ _ _ _ _ _ 14 _

Site 93 (Fill material)04-15-8304-22-8305-12-8305-19-8306-02-8306-09-8306-23-8307-07-8307-08-8308-02-8310-13-8310-27-8311-08-8311-18-8312-02-8303-22-8403-29-8404-06-8404-12-8404-18-8404-24-8405-01-8405-10-8405-17-8405-30-8406-06-8406-20-84

2,0002,1502,0001,9001,3801,4801,580

1,8401,9301,9201,860

1,7601,9501,8501,850

9302,0301,8601,920

1,780

2,200

7.1 -8.0 -7.6 -7.5 -7.6 -8.3 -7.8 -

7.9 -_ __ _

7.0 -7.5 -7.3 -8.3 -7.2 -_ _

7.2 -

_ _ _ _ _ _ _ _ 9.7 __ _ _ _ _ _ _ _ 9.1 __ _ _ _ _ _ _ _ g5 _- - 630 _____ 7.6 -_ _ _ ________ _ _ _ _ _ _ _ 5.9 _ _ _ _ 6.5 __ _ _ _ 7.g __ _ _ __ _ _ _ 7.6 _ _ _ _____17 _

- - 500 ----- 4.7 -_ _ <: Q ^j ^ ~y

_ _ _____n __ _ _ _____io _ _ _ _____n _

_ _ _ _____12 -- _ 540 ----- 5.3 -_ _ _ __ _ _ _ 7.7 __ _ _ _____n __ _ _ _______

- - 550 _____ 9.4 -_ _ _ _ _ _ _ _ 57 __ _ _ _____n __ _ _ _____n __ _ _ _ _ _ _ _ 1Q _

_ _ _ _ _ _ _ _ 12 _ _______

Tables 61

Table 18. Chemical analyses of pore water in the unsaturated zone from on-site, below-trench locations[jxS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; jxg/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]


PH (standard

units)

Calcium Magnesium Sodium Alkalinity Sulfate Chloride Silica Iron Zinc (mg/L (mg/L (mg/L (mg/L (mg/L (mg/L (mg/L (n-g/L (n-g/L Tritium as Ca) as Mg) as Na) as CaCO3) as SO4) as CD as SiO2) as Fe) as Zn) (nCi/L)


Site 26 (Toulon Member of the Glasford Formation)11-17-82 12-10-8203-11-8303-24-8304-08-8304-14-8304-22-8305-19-8306-02-8307-08-8308-11-8308-24-8310-14-8311-08-8311-18-8312-02-8312-08-8303-29-8404-06-8404-12-8404-18-8404-24-8405-17-8405-30-84

765 785

8.5

8.6

8.48.4 8.4

_ _ _ _ _____23

_ _ _______ 28_ _ _______ 31_ _ _______ 26- - - - _____28_ _ _______ 32- _ _ _ _____28_ _ _______ 12_ _ _ _ _____29 29 46 67 - - - 34 50 160 -_ _ _______ 31_ _ _______ 37_ _ _ _ _ _ _ _ _ 14

- - - - _____36_ _ _ _ _ _ _ _ _ 29_ _ _ _ _____52_ _ _ _ _____4g_ _ _ _ <Q^f^f

- _ _ _ _____86_ _ _ _ _____7Q_ _ _ _ _____66- - - - _____53

55

Site 61 (Hulick Till Member of the Glasford Formation)11-17-8212-10-8202-10-8303-11-8303-24-8304-08-8304-14-8305-19-8306-02-8307-07-8307-08-8308-02-8308-11-8308-24-8310-13-8311-08-8311-18-8312-02-8312-08-8301-25-8402-10-8402-23-8403-13-8403-22-8403-29-84

1,180 990

1,0001,0401,040

950990

1,0801,080

990830885

1,000990865875825770970

8.3 8.38.4 7.27.47.27.3 7.47.47.8 8.37.3 7.7

_ _ _______i.i_ _ _ _ _______ _ _ _ _ _ _ _ _ 47- - - - _____3.5- - - - _____3.o_ _ _______ 4.9_ _ _ _ _ _ _ _ _ 28- - - 510 _____ 2.5_ _ _ _ _ _ _ _ _ 17- - - 510 ______

110 78 16 510 53 5.9 65 30 410 1.4_ _ _ _ _ _ _ _ _ 5_ _ _ _ _ _ _ _ _ 7- - - 520 _____ .4- - - 530 ----- .5_ _ _ _ _ _ _ _ _ 2.1_ _ _ _ _ _ _'__ .5_ _ _ _ _ _ _ _ _ 2.6

110 76 16 520 - - 55 10 25 1.9- - - 510 ----- 1.1_ _ _ _ _____4.4_ _ _______ i.o_ _ _ _ _____7.6- - - - _____3.2- - - 490 _____ 8.0


Table 18. Chemical analyses of pore water in the unsaturated zone from on-site, below-trench locations Continued[u,S/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; u,g/L, micrograms per liter; nCi/L, nanocunes per liter; dashes indicate no data]



units) as Ca)



Dissolved Silica Iron Zinc organic (mg/L ((Jtg/L ((Ag/L Tritium carbon

as SiO2) as Fe) as Zn) (nCi/L) (mg/L)

Site 61 (Hulick Till Member) Continued04-06-8404-12-8404-18-8404-24-8405-01-8405-10-8405-16-8405-30-8406-20-84

755

1,000775950

1,0101,020

950

8.2 -8.2 -8.0 -7.5 -

7.5 1007.3 -7.3 -

_ _ _ _ __ _ _ _ _

- - 500 - -_____ 75 15 500 58 3.6______ _ 530 - -

- - - 11- - - 13- - - 6.4- - - 14- - - 17- - - 8.148 20 12 3.4- - - 2.0_ _ _ _

Site 62 (Hulick Till Member)11-17-8211-23-8212-10-8201-13-8302-10-8302-25-8303-11-8303-24-83 04-08-8304-15-8304-22-8305-05-8305-12-8305-19-8306-02-8307-07-8308-02-8308-11-8308-24-8310-14-8310-27-8311-08-8311-18-8312-02-8312-07-8312-08-8301-25-8402-10-8403-13-8403-22-8403-29-8404-06-8404-12-8404-18-8404-24-8405-01-8405-10-8405-17-8405-30-8406-20-84

1,040

950

1,220 _

1,120 1,1501,1201,080 _

1,0801,0601,060

9301,0001,0801,0501,000

915965925

1,0201,020

900975960930935950965950990945945990960900

7.5 -7.5 - 7.4 -

7.2 100 7.3 -_ _

7.5 -

7.4 -7.4 -7.4 110

7.5 -7.1 1107.2 - _ _

7.9 1107.9 1107.3 -

7.6 -7.6 -7.6 -7.6 -7.4 -

7.4 1007.4 -7.2 -

- - 410 - - - 410 - - _ _ _ _- - 390 - - _ _ _ _55 140 350 190 19

______ _ _ _ _ _ 440 _ - 53 66 430 140 20_ _ _ _ ______53 63 420 130 27_ _ 420 - - _ _ _ __ _ _ _ _53 50 410 - -54 49 410 110 33_ _ 430 _ - _____ - - 400 - -_ _ _ _ __ _ _ _ _ - - 410 - - _ _ _ _ _52 32 410 92 35_ _ _ _ _- - 410 - -

- - - 54_ _ _ __ _ _- - - 58- - - 56- - - 54- - - 5942 20 67JO 52- - - 52- - - 52- - - 55- - - 55- - - 55- - - 67- - - 5745 10 370 81- - - 140- - - 15041 8 230 200- - - 390- - - 410_ _ _ 420- - - 400- - - 41043 30 160 38036 5 10 370- - - 420- - - 410- - - 450_ _ _ 440

- - - 410_ _ _ _- - - 450- - - 410_ _ _ 440

- - - 410- - - 42038 90 670 -- - - 450_ _ _ _

_42

67 _ _

Tables 63

Table 18. Chemical analyses of pore water in the unsaturated zone from on-site, below-trench locations Continued[jxS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; u,g/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Specific Date of conductance sample (jxS/cm)


units) as Ca)



Dissolved Silica Iron Zinc organic (mg/L (n.g/L (n.g/L Tritium carbon


Site 63 (Hulick Till Member)

11-17-82 11-23-82 12-10-8201-13-8302-10-83

02-25-8303-11-8303-24-8304-08-8304-15-83

04-22-8305-05-8305-19-8306-02-8307-07-83

08-02-8308-11-8308-24-8310-14-8310-27-83

11-08-8311-18-8312-02-8312-08-8301-25-84

02-10-8403-13-8403-22-8403-29-8404-06-84

04-18-8404-24-8405-01-8405-10-8405-17-84

05-30-8406-20-84

1,170 975

1,080 990

1,020990

1,020

1,040985

1,000

8901,0001,0201,030

970

9601,000

9551,040

860

1,000980815

1,020865

7801,030

955935

1,020920

7.6 - 7.9 - 7.7 -

7.8 1107.6 - _

7.9 -7.4 -7.3 120 7.6 -7.3 -7.2 -

7.8 1206.9 -

7.5 -7.8 -

7.9 -7.5 -

7.6 -7.4 -

- - 410 - - - - 420 - -_ _ _ _ __ _ 390 _ - _ _ _ _ _62 17 350 - -_ _ _ _ _ _ _ 440 - -_ _ _ _ _66 16 440 110 22 _ _ _ _ __ _ 440 _ -_ _ 440 - - _ _ _ _ __ _ _ _ _62 27 440 140 18- - 450 - -_ _ _ _ _______ _ _ _ __ _ 440 - - - - 420 - -_ _ _ _ __ _ _ _ _ - - 340 - -

- - - 4.9

- - - 5.6- - - 4.2

- - - 4.9- - - 6.468 70 79 2.4- - - 5.0- - - 3.8_ _ _- - - 5.1- - - 6.0- - - 4.767 20 16 6.7

- - - 5.1- - - 5.0- - - 5.8- - - 5.2- - - 7.9

- - - 6.1- - - 6.0- - - 6.643 40 350 6.1- - - 6.3

- - - 6.6- - - 7.6- - - 7.2- - - 7.9- - - 7.9

- - - 9.0- - - 11- - - 9.1- - - 12- - - 12

- - - 9.7_ _ _ _

14

23

Site 64 (Toulon Member)12-10-8202-10-8303-11-8303-24-8304-08-83

04-14-8305-05-8305-19-8306-02-8308-02-83

08-11-8308-24-8310-14-8310-27-8311-08-83

9.2 - 8.4 - _

8.5 -8.4 35

_ _ _ _ __ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ ______

290 88 - - -_ _ _ _ __ _ _ _ __ _ _ _ _

- - - 120- - - 120- - 170- - - 120

- - - 100- - - 130- - - 130- - - 120- - - 120

120 50 14 110- - - 99- - - 130- - - 110


Table 18. Chemical analyses of pore water in the unsaturated zone from on-site, below-trench locations Continued[(xS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; (xg/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Specific Date of conductance sample (|xS/cm)


units) as Ca)


as Mg) as Na) as CaCO3 ) as SO4) as Cl)

Silica Iron Zinc (mg/L (|J.g/L (|J.g/L Tritium



Site 64 (Hulick Till Member) Continued11-18-8312-02-8312-08-8301-25-8402-10-8402-23-8403-13-8403-22-8403-29-8404-06-8404-12-8404-18-8404-24-8405-01-8405-10-8405-30-8406-20-84

2,4302,5802,3002,4001,9002,1502,0902,3502,3002,3202,2502,8402,3602,4403,0003,500

8.4 -7.9 - _ _ 8.6 -8.2 -8.3 -8.4 -8.3 -_ _ 8.3 -8.1 -

- - 420 - -- - 340 - -_____ _____- - 520 - - _ _ 820 - - ______ _ _ _ ______

92 96- - - 92- - - 89 oO

oO

90_ _ _ 62- - - 86 80 85 97- - - 95 100 _ _ _ __ _ _ _

54

Site 65 (Toulon Member)12-10-8202-10-8302-25-8303-11-8303-24-8304-08-8304-15-8304-22-8305-05-8305-19-8306-02-8307-07-8307-08-8308-02-8308-11-8308-24-8310-14-8310-27-8311-08-8311-18-8312-02-8312-08-8301-25-8403-13-8403-22-8404-08-8404-12-8404-18-8404-24-8405-10-8405-17-8405-30-84

1,7401,6701,5501,580

1,4601,4901,4901,2201,320

2,6502,2502,2802,1202,0002,290

1,640

8.2 - _ _8.3 -8.2 - 8.5 - 7.8 -7.8 -7.8 - 8.2 -8.4 -8.4 - 8.3 - 8.6 -

__________ _ _ 240 - - ___________ _ _ _ _ _ - - 340 - -- - 340 120 73_____ - - 540 - -- - 460 - -_ _ _ _ _ _____ _ _ 440 - - _ _ _ _ _ _____ _ _ _ _ ______ _____

71 72 77 69 72 77 76- - - 80 _ _ _ __ _ _ __ _ _ _ 68- - - 180- - - 230- - - 230- - - 220- - - 260- - - 250_ _ _ 240- - - 300_ _ _ 300 180- - - 320_ _ _ 320- - - 290_ _ _ 320- - - 340- - - 350_ _ _ 320

41

Tables 65

Table 18. Chemical analyses of pore water in the unsaturated zone from on-site, below-trench locations Continued[u,S/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; jxg/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Specific Date of conductance sample (fxS/cm)

pH Calcium Magnesium (standard (mg/L (mg/L

units) as Ca) as Mg)

Sodium Alkalinity Sulfate Chloride (mg/L (mg/L (mg/L (mg/L as Na) as CaCO3) as SO4) as Cl)

Silica Iron Zinc (mg/L ((xg/L ((xg/L

as SiO2) as Fe) as Zn)Tritium (nCi/L)


Site 66 (Toulon Member)

03-24-83 07-08-83 08-02-83 08-11-83 08-24-83

10-14-83 10-27-83 11-08-83 11-18-83 12-02-83

12-08-83 03-29-84 04-18-8411-17-8211-23-8212-10-8201-13-8302-10-8302-25-8303-11-8303-24-8304-08-8304-15-8304-22-8305-19-8306-02-8307-07-8308-02-8308-11-8308-24-8310-14-8310-27-8311-08-8311-18-8312-02-8312-08-8301-25-8402-10-8403-13-8403-22-8403-29-8404-06-8404-12-8404-18-8404-24-8405-01-8405-10-8405-17-8405-30-8406-20-84

955865

1,100

1,040 990985

1,0601,0201,080

9501,1001,1001,1801,1001,0601,0801,0401,1201,0401,1001,1101,0601,0801,0901,1001,1201,1201,1201,100

1,1601,020

8.6 - -

8.4 - - 8.3 - -

8.4 - -

_ _ _7.5 - -7.6 - -_ _ _

7.9 - -_ _ _

7.9 100 51_ _ __ _ _

7.9 - -7.7 - -7.7 - -7.4 120 66_ _ _

7.4 - -7.4 - -7.3 - - _ _ __ _ _ 7.9 130 687.8 - -_ _ _ _

7.6 - -7.9 - -7.9 - -8.0 - - _ _ __ _ _

7.6 - -_ _ _

_ _ _ _- 200 - -

- 240 - -_ _ _ __ 230 - -_ _ _ _

14 220 - -_ _ _ _ _ _ __ _ _ __ 300 - - 22 300 260 35_ _ _ __ _ _ _- 330 - -

- 340 - - _ _ _ __ _ _ _

28 320 260 28_ _ _ __ _ _ __ _ _ _

_ 320 - -_ _ _ _ _ _ _ _- 340 - - _ _ _ _ _ _ __ _ _ _- 340 - -

_ _ _

_ _ __ _ __ _ _

47 340 120_ _ __ _ __ _ 53 520 -_ _ __ _ _ _ _ __ _ __ _ _

43 290 510_ _ __ _ __ _ _ _ _ __ _ _ _ _ _ __ _ _ _ __ _ _

33 71

1212 27 41 24 3428 15 3416 202021

20 202322212223222225252625261228273232313032333332353636

5.8 _


Table 18. Chemical analyses of pore water in the unsaturated zone from on-site, below-trench locations Continued, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; (ig/L, micrograms per liter; nCi/L, nanocunes per liter; dashes

indicate no data]



units) as Ca)



Silica Iron Zinc (mg/L (M-g/L (M-g/L Tritium



Site 81 (Hulick Till Member)02-25-8303-11-8303-24-8304-08-8304-15-8304-22-8305-12-8305-19-8306-02-8307-07-8307-08-8308-02-8308-11-8308-24-8310-14-8310-27-8311-08-8311-18-8312-02-8312-08-8301-25-8402-10-8402-23-8403-13-8403-22-8403-29-8404-06-8404-12-8404-18-8404-24-8405-10-8405-16-8405-30-8406-20-84

1,1201,020

960920 965890

1,0001,000

810945

1,0201,120

960900920890980900940780915900930920900930930910 940840

7.8 -7.3 - 8.1 -_ _7.5 -7.4 -7.5 -7.5 -

7.1 -7.1 1307.2 - 7.6 12073 __ __ __ __ _

7.5 -7.6 -7.5 -7.7 -7.4 - 7.4 -7.1 -

_ _ 380 - -_ _ _ _ ______ _ _ _ __ _ 440 _ _ _ _ 440 _ __ _ 440 _ _ 62 12 460 109 7.0- - 540 - - _ _ _ _ __ _ _ _ _ 60 11 460 110 6.8

/ion "T.JV.F

_ _ _ _ _ _ _ _ _ ______

- - 450 - -_ _ _ _ _ _ _ 440 _ _ _ _ _ _ __ _ _ _ _- - 460 - -

- - - 1.2- - - 1.8_ _ _ 3 9_ _ _ 1- - - .8- - - 2.4_ _ _ j<j_ _ _ _- - - .2_ _ _ _

- - - 1.2- - - .6_ _ _ 558 1,600 9,700 .7- - - .3- - - .8- - - .8_ _ _ _- - - 1.650 960 1,400 1.0_ _ _ g_ __ _ 9- - - 1.1- - - .9_ _ _ 5

- - - 1.2- - - 1.1_ _ _ g

i 9 I***

- - - 1.3

- - - 2.9- - - 3.5 J. , J

_ _ _ _

_

6.3 _ _ _ _ _

Site 82 (Hulick Till Member)02-25-8303-11-8303-24-8304-08-8304-15-8304-22-8305-19-8306-02-8307-07-8307-08-8308-02-8308-10-8308-11-8308-24-8310-13-8310-27-8311-08-8311-18-83

1,0601,0801,0801,0801,0201,050

1,050920

1,0601,0401,1201,0901,020

9801,020

7.3 1207.2 -

7.4 -7.6 -7.3 -

7.0 130

7.4 -8.2 -7.1 -7.0 - _ __ _

_ _ _ _ _71 22 420 70 14_____ - - 510 - -______ _ 540 _ _73 15 540 66 14 _ _ _ _ __ _ _ _ _- - 540 - -

c/in ,^'TVF

_____

- - - 31- - - 3470 6 440 34- - - 38- - - 39- - - 46- - - 67_ _ _ __ _ _ _63 40 830 110- - - 120- - - 120- - - 120- - - 150- - - 170- - - 160- - - 160- - - 160

8.8 _

Tables 67

Table 18. Chemical analyses of pore water in the unsaturated zone from on-site, below-trench locations Continued[|xS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; jxg/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

Specific Date of conductance sample ((jtS/cm)


units) as Ca)



Dissolved Silica Iron Zinc organic (mg/L (p-g/L (p-g/L Tritium carbon


Site 82 (Hulick Till Member)-Continued12-02-8312-07-8312-08-8301-25-8402-10-8402-23-8403-13-8403-22-8403-29-8404-06-8404-12-8404-18-8404-24-8405-01-8405-10-8405-16-8405-30-8406-20-84

970930

1,0201,0201,040

8651,020

9901,0401,0301,0401,0401,0601,0401,0401,0601,0701,000

7.5 1307.7 1307.2 -

7.3 -7.5 -7.5 -7.5 -7.5 - 7.5 1307.3 -7.2 -

72 13 540 67 1471 14 540 68 14_ _ 500 - - _ _ _ _ _ - - 530 - - _ _ _ _ _- - 550 - -_____ 73 8.9 550 63 15_ _ _ _ _- - 560 - -

- - - 16040 30 130 -34 10 110 180- - - 190- - - 200- - - 200_ _ _ 230- - - 220- - - 220- - - 220- - - 230- - - 240- - - 250_ _ _ _- - - 27050 30 59 300_ _ _ 280

Site 83 (Hulick Till Member)02-25-8303-11-8303-24-8304-08-8304-15-8304-22-8305-05-8305-19-8306-02-8307-07-8307-08-8308-02-8308-11-8308-24-8310-13-8310-27-8311-08-8311-18-8312-02-8312-08-8301-25-8402-10-8403-13-8403-22-8403-29-8404-06-8404-12-8404-18-8404-24-8405-01-8405-10-8405-16-8405-30-8406-20-84

1,2301,0201,1201,050

1,1801,1201,1501,150

9601,1701,2401,1901,1401,0801,1201,0801,2101,1501,1401,0801,0801,0801,1201,1001,1401,1201,1601,120

1,1601,070

8.1 -7.7 - 8.2 -

7.3 -7.6 -7.5 -7.5 -

7.3 -7.2 1307.5 -

7.5 -7.3 -

7.4 -7.7 -7.7 -7.6 -7.5 -

7.5 -7.4 -7.4 -

_ _ _ _ _- - 380 - -_ _ _ _ _ _ _ _ _ __ _ _ _ __ _ 560 - -_ _ _ _ _- - 510 - -- - 510 - - _ _ _ _ _90 28 540 129 19- - 520 - - _ _ _ _ __ _ _ _ _- - 530 - -- - 510 - - _ _ _ _ __ _ _ _ _- - 520 - - _ _ _ _ __ _ 520 - - _ _ _ _ __ _ _ _ __ _ 530 _ _

- - - 10- - - 14- - - 9.7- - - 13- - - 28- - - 38- - - 48- - - 44- - - 37 - - - 34- - - 34- - - 3550 20 160 25- - - 30- - - 30- - - 30- - - 32- - - 31- - - 33- - - 32- - - 34- - - 33- - - 36- - - 35- - - 38- - - 40- - - 40- - - 42- - - 42- - - 42- - - 47- - - 42_ _ _ _

12 _


Table 18. Chemical analyses of pore water in the unsaturated zone from on-site, below-trench locations Continued[|j,S/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; u,g/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]



units) as Ca)



Silica Iron Zinc (mg/L (n-g/L (n-g/L Tritium



Site 84 (Hulick Till Member)11-17-8211-23-8212-10-8202-10-8302-25-8303-11-8303-24-8304-08-8304-15-8304-22-8305-10-8305-19-8306-02-8307-07-8307-08-8308-02-8308-11-8308-24-8310-14-8310-27-8311-08-8311-18-8312-02-8312-08-8301-25-8402-23-8403-13-8403-22-8403-29-8404-06-8404-12-8404-18-8404-24-8405-01-8405-10-8405-16-8405-30-8406-20-84

990860

1,010 810880825860 860720860860740850

1,000890830820750800875840725845585825720810625850825825 870820

8.2 -8.0 -7.7 - 7.9 1007.9 - 8.3 - 8.1 -7.8 -7.3 -7.3 -

7.6 -7.6 1107.5 - 8.2 -7.2 -

7.5 -8.1 -7.9 -8.0 -7.6 - 7.7 -7.5 -

- - 320 - -- - 310 - -- - 340 - - 45 18 300 - -_ _ _ _ _ _____ - - 390 - - - - 380 - -_ _ 380 - - _ _ _ _ _51 13 390 44 7.0- - 390 - - _ _ _ _ _ _ _ 380 - -- - 420 - - ______ _ _ _ __ _ 370 - - _ _ _ _ _- - 380 - - -----

- - 380 - -

- - - .5_ _ _ __ _ _ __ _ _ 2_ _ _ 7

- - - .763 100 140 .5- - - .2- - - .9- - - 2.9- - - 7.9- - - .2- - - .2_ _ _ _- - - 1.1- - - .5- - - .471 10 170 1.4- - - .3- - - .4- - - .4_ _ _ _- - - 2.7_ _ _ _- - - .2- - - 3.3- - - .6- - - 2.8- - - 7.1- - - 6.2- - - 1.9- - - 2.6- - - 1.0- - - 2.1

- - 6.4- - - 2.6- - - 2.4_ _ _ _

13

Site 96 (Hulick Till Member)07-07-8308-20-8308-11-8308-23-8308-25-8310-14-8310-27-8311-08-8311-18-8312-02-8312-08-8301-25-84

910355250250250360395325445346370435

7.2 - 7.6 -7.4 237.9 247.4 - 8.3 387.4 -

- 12 320 49 70 _____10 18 87 33 9.712 16 100 30 8.6- - 130 - -_____ 19 13 150 - -- - 190 - -

81 30 120 2.5- - - 2.4- - - 3.276 60 44 -60 20 71 - - - - 3.3- - - 3.7- - - 3.2- - - 3.840 20 64 3.6- - - 3.2

70

Tables 69

Table 18. Chemical analyses of pore water in the unsaturated zone from on-site, below-trench locations Continued[|xS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; |xg/L, micrograms per liter; nCi/L, nanocuries per liter; dashes indicate no data]

DissolvedSilica Iron Zinc organic (mg/L (n-g/L (n-g/L Tritium carbon

as SiO2) as Fe) as Zn) (nCi/L) (mg/L)Date of sample

Specific pH Calcium Magnesium Sodium Alkalinity Sulfate Chlorideconductance (standard (mg/L (mg/L (mg/L (mg/L (mg/L (mg/L

(|jiS/cm) units) as Ca) as Mg) as Na) as CaCO3) as SO4) as Cl)

Site 96 (Hulick Till Member) Continued02-10-8402-23-8403-13-84 03-22-8403-29-84

04-06-84 04-12-84 04-18-8404-24-8405-01-84

05-10-84 05-17-8405-30-8406-20-84

460375425472400390390440400450460400430400

7.3

8.0 8.0 8.0 7.6

7.6 7.8 7.2

42 20 12

160

160

160

180

42 8.4 39 140

3.4 3.6 3.8 2.9 3.93.9 4.2 4.6 4.6 3.77.0 4.1


Table 19. Tritium concentrations in pore water from soil cores [m, meters; nCi/L, nanocuries per liter; dashes indicate no data]

Location of soil coresGeologic material

Depth below land surface

(m)

Tritium concentration

(nCi/L)

Initial tritium concentration in lysimeters

(nCi/L)

Above trench

Lysimeter 38. ................. Fill material 0-0.15Fill material .30- .46Fill material .61- .76Clayey-silt cap .91-1 .07Peoria Loess 1.22-1.37Peoria Lx)ess 1.37-1.57

Lysimeter 39 .................. Fill material .51- .61Lysimeter 40 .................. Peoria Loess .46- .61

Peoria Loess .79- .94Peoria Loess 1.09-1.24

Lysimeter 51 .................. Peoria Loess . 15- .30Peoria Loess .46- .61

Lysimeter 52.................. Fill material .15- .30Lysimeter 87.................. Fill material .66- .71

Clayey-silt cap 1.12-1.17Lysimeter 88 .................. Peoria Loess 2.26-2.3 1Lysimeter 89.. ................ Peoria Loess .66- .71

Peoria Loess 1.37-1.42Lysimeter 91 .................. Fill material .66- .71

Fill material 1.30-1.35Peoria Loess 2.16

Lysimeter 93 .................. Fill material ________ .41- .46

____________________________ Below trench

Lysimeter II 1 ................. Toulon Member2 0.05-0.20Toulon Member .36- .51Toulon Member .60- .81Toulon Member .91-1.07Toulon Member 1.22-1.37Toulon Member 1.52-1.68Hulick Till Member2 1.83-1.98

Lysimeter 61 .................. Hulick Till Member .25- .41Hulick Till Member .64- .76Hulick Till Member 1.27-1.42

Lysimeter 62.................. Hulick Till Member .05- .18Hulick Till Member .46- .61Hulick Till Member 1.02-1.17

Lysimeter 63 .................. Hulick Till Member .08- .23Hulick Till Member .97-1.12

Lysimeter 64.................. Toulon Member 0- .05Toulon Member .69- .74Toulon Member 1.42-1.47

Lysimeter 65.................. Toulon Member .05- .10Toulon Member .66- .71Toulon Member 1 . 32-1 . 37

Lysimeter 66. ................. Toulon Member .05- . 10Toulo Member .66- .74

Lysimeter 68 .................. Toulon Member .41- .46Hulick Till Member .64- .69

Lysimeter 81.................. Hulick Till Member .05- .20Hulick Till Member .51- .76Hulick Till Member 1 . 22-1 . 37

0.81.25.0

1 116175.01.81.81.9.6

2.11.11.2

1001 ,230

.2 46

.2 1.5

302.1

161822265170363.41.2.8

1717339.54.2

8976100274764141428262.41.0.4

194.8

5.1

1.7 .4

941,230

42

6410

70

1.1

54

4.9

120

70

35

20

2.3

Tables 71

Table 19. Tritium concentrations in pore water from soil cores Continued[m, meters; nCi/L, nanocuries per liter; dashes indicate no data]

Location of soil coresGeologic material

Distance from tunnel liner

(m)

Tritium concentration

(nCi/L)

Initial tritium concentration in lysimeters

(nCi/L)

Below trench Continued

Lysimeter 82 ..............

Lysimeter 83 ..............

Piezometer 27 1 ............

Hulick Till MemberHulick Till MemberHulick Till Member Hulick Till MemberHulick Till Member

. . . . Toulon MemberToulon MemberToulon MemberToulon MemberToulon MemberToulon MemberToulon MemberToulon MemberToulon MemberToulon MemberToulon MemberToulon MemberToulon MemberToulon MemberToulon MemberToulon MemberWeathered shale

.30- .56

.71- .971.34-1.50.05- .20 .64- .79.20- .28 .28- .36.36- .43.43- .51.51- .58.66- .74

1.45-1.521.52-1.601.60-1.681.68-1.751.75-1.832.90-2.972.97-3.053.05-3.123.12-3.203.20-3.283.43-3.84

21 127.75.0 8.3

2633292422425364839799

11014014014017053

31

10

1 Location shown in figure 6; the small number of water samples obtained from the instrument location precluded additional use of data from the location in the study.



Table 20. Chemical constituents in saturated-zone water[|xS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; |xg/L, micrograms per liter; nCi/L, nanocuries per liter; <, less than; dashes indicate no data]

Specific Date of conductance sample (n,S/cm)

PH (standard

units)

Calcium Magnesium Sodium Alkalinity Sulfate (mg/L (mg/L (mg/L (mg/L (mg/L as Ca) as Mg) as Na) as CaCO3) as SO4)

Site 502 (Hulick Till Member of the Glasford06-01-7806-28-7901-08-8008-20-8105-20-8206-22-8207-15-8209-17-8211-19-8209-20-8209-21-8210-13-83

06-23-8207-15-8209-07-8206-10-8310-13-83

06-13-7809-21-7806-27-7901-09-8007-15-8207-19-8206-10-83

06-13-7809-21-7806-27-7901-10-8007-01-8211-19-8206-10-83

6931,030

738907 773

1,350

1,3602,1301,8701,5401,270

1,5201,5802,1001,750

1,960

7.87.46.77.3 8.0 8.4

8.0

6.3

7.46.57.9

6.4 6.97.0

6.5

52413768

41 16

140

10023011011067

160170190150

140

45412340 33 5.5

110 _

130160160140130

130120100150

210

621005765 45 36

Site 505 29

Site 5071823271914

Site 52319182528

42

370460

46470 430

36

71601328 19 89

Chloride Silica (mg/L (mg/L as Cl) as SiO2)

Formation)7.26.3 3.4 2.3

3433 8

14

Iron Zinc (M-g/L (|xg/L Tritium as Fe) as Zn) (nCi/L)

70 - -1,300 - -2,700 - -3,600 - -- - 0.4- - 1.1

1,000 330 1.4- - .9

44 <100 -- - 1.1- - 1.7- - .9


1.5

2.8

(Hulick Till Member) 680 _

(Hulick Till460540620580540

180

Member)340710380310210

12

7.68.77.2 6.1

18

8.71015125.2

- - 80160 1,100 -- - 130- - 130- - 66

_ _ __ _ __ _ _- 180 -- - 8.5- - 6.0

(Hulick Till Member)800800840

1,020

1,150

9911011071

110

182123

23

2222

23

21

_ _ __ _ __ _ _- - 160- 100 150- - 170

Site 524 (Toulon Till Member of the Glasford Formation)06-13-7809-21-7806-27-7901-10-8006-23-8207-15-8207-23-8209-20-8206-10-83

406380457328

500

7.3 7.88.5

9.0

1714138.

19

403738

9 33

56_

11101111

14

170170200170

330

383122

43

2.42.52.92.9

2.5

1.81.01.6

.9

60 - -220 - -600 - -

10 - -- - 1.2120 <50 -- - .8- - 1.4_ _ 2

Site 527 (Toulon Member)06-13-7809-21-7806-27-7901-10-8008-20-8106-22-8207-15-82

756815990863

1,120

1,040

6.2

6.87.57.2 8.0

7662757576

56534864

100

1313131821

330390310450650

94100855959

3.44.85.4 3.5 6.3

9.114132016

_ _ __ _ _150 - -60 180 -

- - 2.5_ _ _

Tables 73

Table 20. Chemical constituents in saturated-zone water Continued[jiS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; jig/L, micrograms per liter; nCi/L, nanocuries per liter; <, less than; dashes indicate no data]

Date of sample


(fiS/cm)

pH (standard

units)


Magnesium (mg/L

as Mg)

Sodium (mg/L as Na)

Alkalinity (mg/L

as CaCO3)

Sulfate Chloride (mg/L (mg/L

as SO4) as Cl)

Silica (mg/L

as SiO2)

Iron (Hg/L asFe)

Zinc (fig/L Tritium

as Zn) (nCi/L)

Dissolvedorganic carbon(mg/L)

Site 527 (Toulon Member) Continued07-16-8209-20-8206-10-83

1,040

8.0

120

87

23

580

80 1.8_ _

21

120

230

2.01.03.5

10-13-83 -_____- -____- - - _ _ _ _ _ 26Site 528 (Hulick Till Member)

06-13-7806-27-7901-09-8008-17-8107-15-8207-19-8211-19-8206-10-83

1,1101,5201,0901,3401,190

7.17.27.47.57.9 7.3

1301408196100 130

758499140100 100

1415171817 17

430560480620530

150120170170220 230

7.737 4.2 4.8

1619121214 16

1901,100

606082 490

150

<100

135.8

51

2.32.6


effects of low-level radioactive-waste disposal on water chemistry … · 2011-03-07 · eters...

Documents